There is a girl in my class that I have a crush on, I can't even talk to her I tried!
I can't stand seeing her every day without her knowing how I feel. I need an answer!

How old are you both?

You are jumping right to 'wanting her to know how I feel' without going through her getting to know you.
Although flattering to know that someone has a crush on you, it rarely results in the person saying 'Oh I like you too.' It might take time! And that means planning a list of some compliments and comments that are about school mostly, so you stay not too personal at first.
'Hey, you are good in history class. Have you thought of a term paper subject yet?'
'Do you think Mrs. Smith is too tough on everyone?'
And of course, as you pass by each other, a smile and a plain old Hi Karen! (After you pass her the fifth time or so, turn around to see if she turned around, and if she did, smile again, and keep walking. Hope she eventually says hey wait. If she doesn't, it's OK to stop and try to ask her if she'd go somewhere with you. If she says no thanks, it's not the end of the world, even though it might seem to be. At least you tried and at least you know.)