My friend likes this girl.. but the girl doesn't really like him.. but he wants to go to the dance.. but she doesn't know if she's going. I need help because I don't know how to to give him an advice

I would tell your friend that he needs to go to the dance have fun and maybe he will meet someone new there. She should really tell him though if she doesn't like him because she is leading him on. I don't think that he shouldn't go to the dance just because she isn't there. Plus have you thought about that she might show up to the dance with someone else and that would really hurt his feelings. I think that you should him the truth before he finds out the hard way. This is just my advice though.