HELP!

I need help! I am having a party for my birthday and its goin to be boy/girl then the girls are going to spend the night afterwards and the boys will go home but i dont know what to do i had the idea to turn the back pourch into a dance floor but we cant dance the whole time! Oh and if anyone has any ideas on how to get my parents to leave us alone and just let us do our thing PLEASE TELL ME!