What are some cheap, fun things for teenagers to do this summer?

I'm 17 years old, and I'm not made of money, but i love the beach and i love trying new things. So i was wondering if anyone had any ideas on what my friends and I could do to spice up our summer? We're from Riverside.What are some cheap, fun things for teenagers to do this summer?
try getting a job and earn some money so you can hit night clubs or something like that.invite your friends to the beach and chill there. learn how to surf with your friends? try learning to long board or skateboard. (skateboard you can learn some new tricks)What are some cheap, fun things for teenagers to do this summer?
I dont have much $ either but things become much more affordable the more people u have.... I recently rented and 8 bedroom house in Tahoe for me and all my friends the whole weekend cost us $100 a couple! it was so much fun but for somethin more affordable spend the day at the beach and have everybody pitch in for food and have a bbq for the night look up free events in ur area lots of ';party'; type of places offer free admision before a certain time althought there will be nobody there at that time it will pack up and pays off to be bored for an hr and have fun the rest of the night 4 free! Im a party planner so I know and for the younger crowd :)