So, go out with her? :shrug:
Or you could say what I'd say. "Great, of course! You can come to my D&D roleplay tonight. We need someone to play the scantily-clad Elven maiden in distress."
And didn't you have a crush on some girl that you were moving far away from or some such situation? Already over that one, too?
Edit: I notice you already told her you'd give her an answer in a few days. Sorry, bud, you blew it. She's not going to wait around for you, and you need to learn to jump on these opportunities, if you know what I'm sayin'. *nudge, nudge, wink, wink*.
Seriously, a girl asks you out, you say, "hell yeah, let's go have fun!" I know your waiting around for that perfect someone, and all, but as David Wolf said, "Idealism is what precedes experience, cynicism is what follows." You'll learn in time.
I remember when I was fifteen. There was a girl in my class, let's call her Brianna, even though that was
not her name. Brianna was a feisty one, a little hot-tempered, but very direct, very open, with a bit of a thing for guys that don't get the girls. You know, the chubby, the geeks, and so forth. Even though she was a fox. Oh yes, indeed. Brianna, oh Brianna, how I longed to go back in time and give you my phone number when you asked, which I hesitated to and decided not to, because I wasn't "sure" about you. How I longed to go back in time, and experience my hands exploring every supple inch of your perfectly sculpted b-...ahem. Brianna never asked me again, and soon found herself another man, who was apparently much wiser than me.
The point is, you can't turn down a girl because you don't have feelings for her. Love and affection for someone is something that you develop after spending a lot of time with them, after becoming close friends, and finding trust in one another, and sharing experiences. When I met my fiancee, I was just picking her up and bringing her to the supermarket as a favor for a friend of mine. I had no feelings for her whatsoever, of course, I hardly knew her. Yet, we ended up meeting again, later on that night. Over time we became good friends. And then, well ...you know where things went after that.
You'll learn in time. For now, take advantage of these opportunities when they come, because they will be few and far between, and good, or bad, they will be worthwhile experiences, and you never know where they'll lead.