Gosh, I remember agonizing over that same problem when I was a teen. I used to rehearse what I would say. I was so nervous but I pushed myself to just do it. I would have to say that the best way forward is to try to find a natural situation, like being in a conservation about something while just hanging out, and then casually saying something like, "Hey, would you like to go out sometime, say to a movie or to get a milk shake?" If that doesn't work you might just have to bite the bullet and call her on the phone. If you can start with asking about a homework problem or something and then "test the waters" and carry on a conversation about something at school or of mutual interest, and then pop the question, "Say, I was wondering,...". Good luck young man!
if you are really not ready for girls then dont worry about it but what i would say as a teen girl myself. Just go up and ask her get it done and over with! or if you're to shy go ask someone else that you trust to ask her out for you,or wright in a note saying do you want to go out ,or even on a cellphone.
well i think that you should work with her on a class project and the you could ask her on a date. if you think that you are a shy person you should not be one because you don't or I hope that you do not suffer from poor self esteem. so you must do what you think that you are ready to do and don't worry if she does not want to go out on a date with you their are lost more girls that you can go out with.