I asked a girl to homecoming and she said yes. The problem is she said she would meet me there because she already said she was going with friends. She said she would hang out with both her friends and me. Am I in the friend zone?

I'd say yes you're a friend to her along with her other friends.  Usually asking a girl to homecoming means you escort her there and it's understood she's with you.  This is not what's happening in this situation. 

I would ask her outright if she considers she's your date or if you're just hanging out as friends because if she's not your date then say you'd like to ask someone else. If she says she's not your date then feel free to ask someone else and who knows when she sees you're not just waiting for her you may become more attractive to her. 

Don't let her use you as a doormat.

Right now, I would say you're not very high on her list of worries. It seems to me she's more worried about hanging out with her friends than she is going to the dance with you. You're probably very heavy in the friend zone right now.

You are! She jut desperately needs someone to pass the time so she took you. She takes you as a friend , or just a friend!