How do i ask out a girl who hasn't gone out before?

Well neither of us have really gone out but what im really afraid of is that since her and her friends are pretty much against dating untill you're 16 (Before you start going omg it is a private Christian school with only 20 people per grade) she will probably get really nervous if I ask her and say no which i couldn't really afford cause id never get a second chance to ask her or other girls i wouldnt mind going out with again. Another problem is her parents, a few years ago one of my friends said he liked her she said she liked him etc., etc. Then her dad found out from checking her IMs and my friend completely forgot about her since he though it wasn't worth the trouble. I really would like for her to not get in trouble if she went out cause that doesn't really seem right and i don't want her having to deal with being forced out of another relationship. We are both 14 and are going to be going to diff schools next year but i don't think that would be much of an issue if i got a healthy relationship started. Also her friends may mock her for going out with some one cause virtually no one is mature.