I think you should first focus on becoming friends with the girl that you have a huge crush on. Then, when the friendship is developed you can easily let her know how you feel for her and see how she responds. Just be patient and give it time for love to grow.
just ask her out. or hand her your number and say: Hey girl, call me maybe? or better yet, find a cute way to ask her. try this: if she has your number and you have hers, then text her a picture of you holding up a small sign saying: Date?? yes/no and hopefully she'll say yes!!
Girls are pretty sensitive about hints that you might give that show you have an interest in her. We can pick up on them pretty easily! The next time you're around her, have some courage and strike up a conversation that leads towards an opportunity to compliment her. After saying something nice about the way she looks or her personality (e.g. You've just made her smile by saying something funny, so you say: "I love your smile! It's so cute!") She might blush a bit, but don't worry, it'll make her feel good! Then you can just ask her if she might consider ever going out with a guy like yourself.. Make sure during your time around her that you use body language and verbal language to let her know that you are happy around her and that you like her. Good luck!!