My son will be 3 in a few weeks and I am concerned about his total lack of interest in potty training. He refuses to sit on the potty (the big one and little one). How will he possibly train if he won't even sit down on the pot? Do I have reason for concern? Will he just do it one day when he is ready?
First off, three is a common time to start potty training. My oldest didn't start until that time. Some children are faster and some are slower; I wouldn't worry about the timing. Honestly, unless you have a specific need (i.e., a school or something that requires it) I would recommend waiting until he is ready (meaning until he's happy to do it). Training before that point will be stressful for all involved. Training at that point will be quick and easy in most cases. Give him a bit of introduction for now, make it seem fun, maybe read some books to him on the toilet or similar. He'll get used to the idea of it being interesting soon enough.
Second, I strongly recommend to skip the "pot" entirely. We didn't use it for either of our children, and personally I see very little benefit in using a separate child's potty. It will make it harder to transition to out-of-house toilet usage, as the child won't be able to use a child's potty there. Instead, use a child's seat on your regular toilet if you need to; those are much easier to transition away from.
I have eight children. Each one developed the "skill" at a different age.
From my experience, believing that a child must achieve some objective by a certain age is not useful, unless it is way off as an indicator of a possible genetic defect or health issue. Normally, they will do it when they are ready.
We did not force it, but encouraged it by making it a "rite of passage" from being a little baby to being a kid. What we did, because we are a technology family, was when they were potty trained, they got go out with their mom and dad - alone - no other kids - have a nice dinner and then pick out a new computer for their own. Super exciting for a little one to be treated like a "big" kid.
This turned to be rite of passage for them. The younger ones saw the older ones with computers and wanted one and found out from the older ones what had to be done. Once they figured out the "you're too little, you still use diapers" concept, they did all the work at their pace and made it happen.
Not only did they do it, but they were PROUD of their achievement - gleaming with pride at their success - as they should be.
This even worked for the oldest, who saw dad with a computer and wanted one and was told what needed to be done to achieve their desire.
Bottom line, you leave it up to THEM. Treat it as a POSITIVE achievement for THEM. Not only will they do it themselves, but they will be smiling ear-to-ear when they have done so.
From my own experience (as a parent), pot is not always a required step.
Both of my children also refused to sit on a pot, so instead we bought a toilet training seat, so they can sit on the toilet itself safely.
I can't know if it was faster or slower than "ordinary" potty training, but eventually they got the hang of it and got fully potty trained.
So my advice is to try this method as well, since refusing to sit on a pot does not always mean refusing to become potty trained in general.
Kids are all different. Worst thing you can do is stress about it. My oldest trained in 3 days when she was just about to turn 3. Second was not till 4 and youngest was trained at about 3 and a half but had nighttime issues for a while longer.
It will happen eventually. Just be calm, patient, and willing to try different approaches.
Remember, there's not a lot of 4th graders running around in diapers.