So formal (prom) is going to be happening in a couple of months (February) and I want to form a good friendship with my crush so I can ask her out for the formal (We re both 16 btw). The main problem is, she doesn't t know me all that well and the only thing I ve ever been able to say to her is "good luck" before exams and I said "hi" once in the corridor. She always sits with friends in class too :(. I know I have to strike up more conversation but the main problem is she s always with a group of female friends so I'm even more nervous to approach her in case she acts up because of her friends near. I get butterflies every time I hear her voice and see her face but I don t know much about her. I want to though! I feel I never get the right chance to be alone with her and just talk. I had an idea of calling her in the hallway to the side so I can have a chat with her and I d tell her she looks beautiful and ask her if she d like to go out with me sometime, but I feel that might be a bit weird. Help please lol.

Be confident , try to attract her by being gentle smart good looking and even excellent in studying. While doing that keep saying Hi to her. After awhile u will see , she might tries talking with you. Or at least you will be sure she won't refuse your invitation. Good Luck

Not only is it too soon to ask anyone to the prom, but you don't know her well enough, and are setting yourself up for a big fat no.
You need to be spending a lot more time saying hi in the halls! And not a shy mumbling hi, with no eye contact, as you rush by. A cheerful (but not fake) hi, a 'wow am I glad I ran into you' hi, with a smile and enthusiasm. You don't need to pause more than a fraction of a second, but enough to let her know that you wish she wanted to pause to talk. Then keep on walking, and don't look back. Do this at least 10 or 15 times over the next month, and then decide what the results are. Does she frown, or turn away? Then consider yourself out of the running. Does she say hi back, but without feeling? Then keep saying hi, but don't get your hopes up. If you see a tiny bit of hope, give her a compliment on your way by. Nice shirt, I like your hair that way, I like what you said in class.
Your fantasy about calling her to the side of the hall to tell her she's beautiful and so on is WAY over the top. (BTW, a couple of months is 2. Your prom is over 5 months away.) Take some deep breaths and go SLOOOOOOWWWWWLY. Practice what you will say. The way you are going is guaranteed failure. Remember - cheerful, friendly, and complimentary!

This may scare you even more my friend, but I would not be afraid to engage my crush around her friends AT ALL. She will likely share it with them anyway so be bold and unafraid. Just be friendly and give them something to talk about. You have NO reason to hide your crush from her, or her friends.

Never fear rejection, knowing how SHE feels about you (good or bad) is a lot more important in the grand scheme of things.

She certainly won't go to a dance with you if she doesn't know you and you may not like her if you really knew her, so get over your shyness and start talking to her. Make a habit of saying hello even day. You'll soon know whether she is interested or if you are still interested.