What do I do if I like someone, but I dont know if they like me back?

you could always ask them or you could get to know them a little more go out for a coffee or drink ... and get to know each other and spend a little time

Well first off, does she know you are Bi as well? like are you open about it?
if she knows you are, do what Rebecca Joyce Thompson said, ask her to go to coffee or something, get to know her and read her signs. And, if you really really want to go out with her or whatever, be open with her about how you feel, if you are ok with potentially ruining the relationship.

BUT, if she doesnt know you are bi, than first off tell her too, somehow. without it looking weird.
but yea in a situation like this, basically play it cool until you get more information on her feelings towards you.. because this is all kinda new still so take things lightly until you have a better idea on the picture. GOOD LUCK! hope it all works out ^_^

just be yourself, try to join some of the clubs she's in and get to know her a little bit. That's when you start the relationship. Good luck!

Your friend cares about you. I agree that you should definitely express your feelings. But also tell her you are afraid of losing her, and that no matter what you want the friendship to last. She sounds like a really amazing person, and from what you've said, very understanding. Be gentle with the matter, but the only way you will know is to ask. Best of luck!

I say test the waters first by hanging out with her more often and just enjoying each other's company. You never know what she really feels about you until she says it in the open. I definitely do not think she would hate you as a result of your confession. Just slowly approach the topic and consider her feelings by asking her if she's comfortable with where you're headed. It can be overwhelming when someone confesses their love to you so just word yourself ..delicately, but most importantly don't forget to just be yourself. Sometimes wording yourself too carefully can cause you to come off like a different person. If you're going to express yourself I recommend you just say it from the heart.