Crush is a stranger, how do I get to know her and get to date her?

So I’m 16, and I have a crush.

I like this girl, a grade above me. I’m at a disadvantage because I don’t have much of chance of approaching her. The only time I see her is in lunch and there she is surrounded by her friends, and I am too. I don’t know how to attract her attention or approach her for that matter. I can’t just walk up to her and say “Hi.” can I? It would be awkward for the both of us.

Now I don’t know much about her, but sometimes I see her alone doing her homework or simply working alone. I think there is a chance there, to talk to her but then again, how should I go about this?

There are a lot of questions and I’m pretty new to the “dating” game as it were.