I am currently at a young age and have been programming for several years.
I was first introduced into C when I was around eight, although I haven't touched the language much. I focus more on web development and design, although I have fundamental knowledge of Java for the Bukkit API and I will soon be expanding onto either Objective C or Swift.
In my current experience, it's best to learn via yourself. I find it more difficult at a younger age to learn from other people, but rather trial and error. I know that many schools offer computer clubs and such, as to which I was asked to attend but denied, although I don't feel as these suffice for me. Being a younger age, people generalize that us children are not capable of what they expect. I know that I'm more knowledgeable with various programming and scripting languages with many adults that assume my level of knowledge on the subject.
When I first started with programming I would watch many online tutorials, although only visual tutorials would help me. Reading and interactive resources wouldn't help me at all, although videos also limited me.
I would copy code from videos and explore how it worked. I would research certain functions and experiment with the language until I had intermediate knowledge of it.
I feel as though being a child, I'm limited to what I can achieve. Theoretically, I could be classified as a 'Nerd' or such for having such a broadened range of knowledge for computing and programming, although it isn't much help for me. I'm unable to focus my full time on computing and programming for barriers such as school, family and friends. If I were an adult, I believe that I could expand on my knowledge quicker and learn more, although it's different per person.
Anyway, if you don't want to read my cluttered text, I just recommend letting the child learn by himself. He's most probably in the same position as me feeling limited, although if you leave him be I'm sure he will find resources that help him rather than being given resources that won't help him.
I apologize for any grammatical errors for I am still a child myself and am not capable of writing in detail or in the structured way an adult with more experience and knowledge would be able to.
I hope my information helps however, even though it's quite broadened information.
Edit: I would not recommend using tools such as scratch or auto-completion or automatically generated code tools as these would defeat the purpose of programming. Scratch consists of common sense rather than programming - this isn't how one should view programming.
the fundamentals of HTML, CSS, and JS, which I don't know anything about (I'm not a programmer)
says the person with 4k SO reputation and whose top tags happen to be HTML, CSS, and JS