I want to ask a girl out. Theres alot of these questions. Any answers?

I want to ask out a girl really bad but can never find her in school and when i do shes by her friends and i might get embarrased if i get rejected. Snd when shes all alone and i have my chance i get to scared. And i dont want ask her out through a friend or facebook cause that seems like a bad way to ask her. Ahh i hate my life. She would make my life better. Haha