Dude your 15.... ask her out, if she says no, oh well, your 15. When I was 15 all I thought about was hitting home runs in the summer and snowboarding in the winter. Find out what she like to do. Not stalker style, but you guys have a lot of the same friends, so it should be pretty easy. If you get her to hang out, drop the old "do you want to see my fish tanks"(that are in your room), if she says yes, money. If she says no thanks, oh well, YOUR 15. Be yourself, don't get hung up on a girl, and don't loss your friends over this.