Dont Know What To Do

My stepdaughter is turning 13. We are thinking of a swimming party and a DJ for music. We have the location set and DJ is a friend of mine so I am not spending a fortune on him. The problem we are running into is the fact that her friends live in the same city as she grows up in(lives with her mom, we are N. Of them about 30 min and the party is going to be held S. About 30 min.) and she wants them to come. She also wants a coed party. She wants to have a few friends to spend the night as well. We are trying to figure out the transportation thing and sort of the theme, like for the invitations or something. She is a big anime fangirl and loves Naruto. Can anyone help? We have a month before her birthday.