What are some fun things to do in los angeles, more like what locals do?

I am going down there soon, and need to find things to do, not touristy, like visit disneyland or universal studios, but more like any summer concerts, free comedy, tv shows that 15 years olds can go to, tickets to shows, markets, etc. What do locals do down there and for cheap or free if possible. I am on a very low budget and I can't go surfing, clubbing, etc or anything expensive. Please Help, I have no idea what to do down there for a week.