One of the things you could do is try and intern at a tech company during the summer. The main benefit is that you'll be able to see how different technologies are usually put together to make a product, and will also learn some useful professional software development practices along the way which may become handy in the future in case you ever decide to do a startup.
Since you're not in college yet this may be slightly difficult, but as long as you have put together a portfolio of interesting things you've worked on (which you clearly have), it shouldn't be a problem.
I'd argue the intern part may not be necessary. If he has skills like he says, he could probably just about land a front-end web developer job for a few months with decent pay.
I'll second this. Seeing how an establish company does software ( revision control, testing, rolling out updates, etc.) taught me a lot about programming that I don't think I would have learned anywhere else.
Since you're not in college yet this may be slightly difficult, but as long as you have put together a portfolio of interesting things you've worked on (which you clearly have), it shouldn't be a problem.