Stormz said:
What I need to do is find a good point where I can do it. Unfortunately the only time I can catch her without her friends around is in the morning when we're in English, but if I tell her I want to talk to her after class she'll either know exactly what I'm going to say already or ask why. I wouldn't have an answer for why because I don't want to have an audience, especially not with people I have to spend the rest of the year with.
Try to make the invitation as casual as possible. Don't attach a lot of pomp and ceremony to it...there's no need to issue an invitation to a conversation wherein you issue an invitation. Asking someone out takes < 10 seconds. Presumably you've already got a time and activity in mind? (And if not, you should). "I was wondering if you wanted to go to X with me on Y". Like ripping off a band aid. Resist the urge to color the invitation with self-deprecation or defeatism. Act like you're inviting her to do something fun she's sure to enjoy. Since you almost certainly will not be FEELING confident, you're gonna have to fake it.
And most importantly, if she says no, be polite and respectful and shrug it off. Don't run off howling or call her a name or act like you just got stabbed. You can curse the fates later in the privacy of your abode.
Conversely, if she says yes, do try to keep an even keel. This is not a sprint, this is a marathon. A first date is the starter's pistol, not the finish line.