Sweet 16 Birthday Party Ideas?

I am turning 16 this year in October. My party is on the 24th on a Saturday. I will be having about 15-17 people be there. Mostly girls and idk if any of the guys I'm inviting can come.

The girls will sleepover and obviously no guys can, cuz of my mom. I live in a pretty good sized house with a big backyard. My backyard has 2 sitting areas that take up a good amount of space. I want to do something outside game wise! I already have a few ideas, but not enough if people get bored. The only problem is that I wanted to go swimming, but I can't with my party now.

I don't know what else that's kinda the main event to do anymore. It can't be expensive almost at all and transportation might be tight only having 1 or maybe 2 cars. I really need game and activities ideas asap. We will be in and out of the house a good amount of the time! Please help me!