If you can, take a Computer Science class. This is normally something some schools don't offer. I know mine does, but it's not that great. Teachers suck, blah blah.
Anyways, I don't think this is offered to teens @ school, or as an outside course, and again, I'm speaking based on what I've seen, so prove me wrong if you want but yeah.
If you aren't attending University, then this is something you're going to have to self teach, or wait for Uni.