13th Birthday Party.

Heyy. Um ok im going to have my 13th birthday party in july. And im inviting about 20 ppl. I need some help on fun stuff to do. We have a pretty big house and a pool so we will def go swimming but i want to do somthing else too. I guess we will prob play some volleyball and make ice cream sundaes but i want to have somthing else planned too. At my last party i didnt plan a lot of stuff to do and everyone got bored.