Oh god, Blink 182. This man's deeper in sorrow than anyone I've ever seen.
Jokes about musical taste aside, you really shouldn't get too worked up about the whole situation. I've been rejected in various ways (running the gamut from "you're sweet, but I already have a boyfriend" to "no, **** off and die") far more times than I've actually gotten with a girl. See, here's the thing with girls that seems like common sense but is just so hard to pull off: just be straight-up when asking them out. Each girl is different, but they all have one thing in common: the more effort you put into asking them out, the more your chances of them saying yes plummet.
Just be yourself, but not obnoxiously so. Dress nice, yadda yadda. Try and get her number, but don't ask for it. Trust me, if she's into you, you will get one. The three-days rule doesn't apply as heavily to high school since you'll probably be seeing her on a regular basis, so call her up maybe a day or so later in your case. While conversing, ask more questions than anything else, since at this point, to be honest, she doesn't care too much about what you think and just wants to tell you about herself. If she's still into you after a while, ask her out. Seriously, that's about it. What follows after is, unfortunately, not as easy to map out. And if she says no, then take it in stride. Tell her it's cool, maybe some other time?, that kind of thing.
In short, pretty much any guy can get a girl as long as he's confident, nice, gentlemanly (but not too gentlemanly), and plays it cool.
