Well, you have to be patient. My advice is to try and find places where musicians socialize... which isn't easy at 14, but here's one idea: if you get lessons ask your teacher. I know a guy that referres students to all kinds of people to jam with, or for serious projects. Your teacher (if of course you have one) probably knows all kinds of people your age with your interests who're looking for a band. So that's one place to start. Finally, I've always been a bit more comfortable playing with musicians my own age, but hey, we're all different.
Well, goodluck.