so you asked her if you could ask her out, but you're too shy to actually ask her out..? wtf?
^^^ never heard of a situation like this before lol
instead of asking her like "do you want to go out with me" or "will you be my girlfriend" say something more along the lines of "i was hoping we could get to know each other on a more personal level and see where it takes us"
after that? well, get to know her more personally. talk about things you already know she likes to get her talking, and just let her keep talking, be genuinely interested in her and her life,
pay attention. make random, positive, thoughtful comments every now and then when you're hanging out like "i like your shirt, that's my favorite color" or "i really like what you did with your hair, it looks cute" girls love it when you notice and appreciate the effort they put into making themselves more attractive. a
little teasing here and there but don't say or do anything at all that would make her self-conscious or uncomfortable. be a gentleman, be confident, take her to wwe super slam, do everything zack said. all of this gets easier and becomes more natural with practice, and since you're only 17 it's a great time to start practicing