I'm a 27 year old trans woman, the atheist daughter of a pair of conservative, queerphobic christians. While I didn't figure out my gender until my mid twenties, I came to be an atheist at ~12, strongly suspected I wasn't straight at 16, was cross dressing intermittently back then, etc etc. All of which is to say, I kept a lot of secrets from my parents because I didn't think they would understand. I understand where you're coming from here, what you're facing/fearing, but also why you want to come out, why keeping this secret is also hard and scary.
I don't think I can really answer this from a parents' perspective - I'm not one, and I don't have those instincts. But I want to offer a perspective that's more respectful of your needs as a trans person than what has been offered so far by other answers. Hopefully that's enough to give this answer merit here.
I also want to say that I'm really proud of you for thinking through this so young. It's so impressive, and so cool, to see young kids coming to grips with their gender & sexuality, instead of avoiding the question & being miserable. What you're learning about yourself now is really powerful, even if it doesn't end up being exactly right - the fact you're exploring & trying things is good on its own.
Okay, so what do you have to take into account when deciding when & how to come out? I'll go in to how to answer these considerations in the next section, since that's the core of your question, but let's start here.
- What are the consequences of waiting? Will it affect your mental health? Your grades/work?
- Will you be safe? Are you in danger of abuse or being disowned?
- Will you be supported & affirmed?
- What support system do you have?
- How independent are you?
Expanding on each of these:
What are the consequences of waiting?
Being misgendered hurts. Pretending that you aren't attracted to people you are attracted to hurts. Hiding parts of yourself hurts, and it does permanent damage to your relationships, both with the people you're hiding those things from and the people around you. You miss out on experiences, relationships, your whole sense of time & the progression of your life changes. I think this is the thing other answers so far have missed - they aren't really accounting for what staying in the closet does to you.
So, think about what the consequences of waiting are. Whether that's something you're okay with, or something you can endure. Maybe it's something you can endure for now, and you'll reevaluate later. Maybe it's not, that's okay too. That's something you'll have to think for yourself about.
Will you be safe?
If you think you're going to face abuse or neglect for coming out, that's a strong factor to consider. I will say this, as a positive note - the days of getting kicked out for being queer are receding. It happens less often now. And abusers are less likely to get systemic support. Things are getting better, even if this is still something you have to think about.
Will you be supported & affirmed?
On the flip side, if you are going to be supported and affirmed, that's a strong reason to come out ASAP. If you've got family who will not just tolerate you, but actively help you be who you are, that's great, and you should take the opportunity, because it will be better for you all around :)
What support system do you have?
For instance, do you have friends who know you're agender and can be a listening ear? A teacher who is sympathetic and will go to bat for you? A community organization that stands up for queer kids? These things all help making coming out safer. And yeah, finding these things, making a support system, that requires coming out to people, but you can choose your battles a lot more strategically here. You can pick out people who you know will support & affirm you before you come out to them, and then it doesn't have to be as scary.
How independent are you?
This is a hard one. You're 13, you're not going to have a lot of independence. You just aren't mature enough for that, and that's okay - you shouldn't have to be. But, some level of independence can help. If you were a little older, I might ask if you could drive, if you had a job. If you were even older, I might ask if you had savings & could afford to move out if needed. Those aren't options for you, though, and I'm really sorry that this is something being asked of you.
So, the question then becomes, how do you find out the answers to these questions you're considering? How do you figure out if you're going to be safe and affirmed?
You've obviously done some research, you know the classic answer - talk about LGBT celebrities. That doesn't work for your situation. Here are some other ideas:
- Talk about LGBT issues in the news. Maybe pepper it in with other social issues you care about, as a smokescreen, as a way to build skills, as a way to get information about their wider political views which is also informative. This is hard to do when your political views clash - believe me, I get it, I had more than a few angry arguments with my father, back in the day, even when we were both more centrist - but it's the most surefire way of getting their opinions, and possibly changing them.
- Talk about queer/queer adjacent people in your life (even if you have to make them up). Talk casually about your female friend's girlfriend. Mention your male friend wearing nail polish one day. Talk about your new agender teacher.
- Do or make up school assignments that talk about queer things. For instance, say you have to do a book report on a book that has queer people in it, and ask your parents to proofread it. This might sound hard to have it not result in your parents questioning why you are choosing to do those things, but it's totally possible if you're careful - as an example, one of my classmates once picked as a research topic "Don't ask, don't tell" thinking it would be about military secrets (aliens), but it was just about a US military policy towards gay people. You're young enough that those kinds of "mistakes" are totally believable.
This doesn't just have to be directed at your parents, either. This is equally effective at finding a wider support system - talk politics with your friends & see who's cool, turn in LGBT-related assignments to your teachers & see who's positive, etc.
How do I come out as agender?
Being out isn't a binary. It's not that you're either in the closet or out of it. Especially as a nonbinary person, what you're going to find is that you're going to have to come out to new people all the time, for the rest of your life. That gets easier with time - you get the hardest ones out of the way earlier, and you get better at it as you do it, but there's never a point where boom you're out to everyone. And even with 1 person, coming out isn't a binary, you can be out to different degrees, depending on what you tell them/what you ask them to do.
So I'm going to highlight a few different options, a sliding scale of "out" that you can pick and choose from, depending on what you answer from the considerations. There's no wrong answer here - being out, finding love, being trans, those things are all for your comfort, and no one else's, and as long as you're comfortable with where you're at, that's what is right for you.
Come out to your parents, fully, as agender & pan/demi
Most obvious & full answer first. Tell your parents that you are agender, and that you love people of all genders, and you hope that they will continue to love & support you.
Here's what to make sure to tell them:
- Who you are & what that means (a person with no gender, who can see themself loving people of all other genders. Or whatever your labels mean to you personally)
- What is going to change with you (New pronouns? New name? New clothes? Whatever it is that you are going to be changing)
- Who should & should not know (which is this whole thing over again. Coming out is never over, but it does get easier with time)
- What you need from them (using your new name/pronouns, mental health support, puberty blockers, whatever is your "next step" from them)
Options for the format for coming out:
- A face to face conversation
- Read them a letter you wrote
- Give them the letter, or send an email, or a text even, etc.
- Call them (this is standard advice, but is kind of hard for your situation. Maybe from a supportive friend's house?)
- Whatever else you can think of
Beyond that, there's any number of things you can say, and all sorts of advice for how to help them have a good reaction. I leave searching that as an exercise to the reader, these are just the minimum things you should try to communicate, in my opinion.
Don't come out, but ask them to start making changes that make you feel affirmed
You don't have to be transgender to use a new name. Ask them to start using a new name. Or, ask them to start using a nickname instead of your birth name. I'm thinking about a story of an enby who, long before they came out or even knew they were nonbinary, asked people to call them Truffles, and then refused to answer to any other name besides Truffles, until people just started to use that as the default. Or, when in high school I started readily answering to Shelby so much that it became the name a couple friends used for me all the time for about 6 months, even if it was a joke.
You also don't have to be trans to wear clothes you're comfortable in, or to have presentations you like. Want to wear that shirt? Just wear it, regardless of what other people say. Nail polish your thing? Rock that look. Hate dresses? Don't wear dresses, wearing a nice suit instead.
Or you can just tell people to stop referring to you in ways that make you uncomfortable, or to refer to you in ways that do make you comfortable. You are allowed to say "this makes me unhappy, please don't do that" and have that be respected.
You can live pretty comfortably doing this, for a long time. Part of the reason I didn't realize I was trans until my mid twenties was because in my early twenties, I decided to just do the things I wanted to do, damn other people's judgement. And it helps, even if it doesn't make things go away.
Stay in the closet
Ultimately, you don't have to come out, you don't have to assert yourself, you don't have to do anything. It's totally valid and understandable to stay in the closet, if that's the safest thing for you. (To be clear, safest holistically, including whatever it's going to cost you). No one should judge you for that choice.
I do suggest you do things to make it easier, though. Find places you can express yourself privately. Find people you can commiserate or celebrate with. Plan for & build a future when you don't have to be closeted, and work towards that, in whatever way you can.
But also, find other sources of joy. You're a multi-dimensional person, your gender & sexuality alone do not define you. Build on those other pieces - join a club you fit in with, find hobbies you love, learn things you're proud of. Make your life one you're happy with now, not later.
You're 13. You're growing up, you're really starting to become your own person. You're definitely still a child, you still have a lot to learn about the world & yourself, but you're getting to an age where you know more than you don't. You're getting to a point where you can be trusted to set your own boundaries, and where your parents should respect them, at least where they are reasonable. You have the right and the ability to say no, and for the most part, your parents should be respecting that, especially when it comes to things like "I don't want to be called that."
But, your parents have to adjust to that, just like you do. In some ways, you still feel like the baby they had to do everything for. The more you can show them that's not true, by showing your own maturity, the better they will be able to adjust.
Setting appropriate boundaries is critical to coming out to your parents as a kid, especially as trans. So I want to highlight this particular, and point out a couple of things that I think help present you as mature enough to be setting them. Classically, I use hair cuts as the example, because all kinds of trans people have to fight their parents about hair cuts, but this is not just about hair cuts.
First thing is to just say your boundary. If your mom says you should style your hair a way you don't want, just say "no thank you, I would like my hair to look like this." If she says it again later, repeat yourself a few times just in case she needs a reminder. If things still aren't clear, then sit her down and firmly establish that boundary. You want to show:
- You understand the consequences of your action (your hair might look bad for a while, you might get teased, you might have to learn how to take care of a new style, etc)
- You are happy to accept her help dealing with those consequences if she wants to offer it (she can teach you her hair care routine, the two of you and a hair dresser can work together to find a nice style, etc)
- That this is your decision to make, and you definitely want it. You don't have to explain why, if you don't want to - "I want to have this hair style" is a complete reason to have a particular hair style, most times.
Then, you just keep reasserting that boundary. This does mean you have to follow through on those things - you have to accept the consequences, you have to let her offer help, you have to have some conviction in your decision - but it matters a lot that you have set the boundary.
It's hard, but it's really valuable and really important, and such a good tool to have in your pocket.
Welp, this got longer than expected.
Tl;dr: Consider what's safer, and include in that consideration what effect being closeted will have on you. Try and gather information to help you figure out what effect being closeted/not closeted will have. Then, once you know what feels safest, come out to a degree that you are comfortable with, which can be any number of things over a wide spectrum.
It gets better. Every day I live as an adult, every moment I am my true self, is better than any day of high school was, and I really enjoyed & valued high school. So trust me when I say, no matter what happens, if you just keep moving forward, there's a bright future waiting, and I'm really excited for you to get there to see it :)
Sources & further reading
I just skimmed most of these, looking for particular pieces, plus they're probably all very centered on American (or at least Western) values, so take what you can from them, but don't hold anything as the be all end all. Including what I say, of course. You know your life better than I do.