I'm not much for car camping but if you want to get a big group together and sleep outside Cachuma has a ton of nice group spots. There are picnic tables, fire pits, bbq pit and even electricity to charge your phone.

There is a general store, a disc golf course, and a mountain biking trail. You can't swim in the lake (which is dumb, they say it's because it's drinking water but you can put a boat in and fish and I'm sure boats and fish have as many germs as people) but there is a pool. You can also rent kayaks and other water related toys.

The main draw back is that you're all over every neighboring campsite and the bathrooms were soooo, so, so disgusting. There was used toilet paper all over the floor, one broken sink, backed up toilets, ect ect. They cleaned them pretty often but blink and they were gross again. I would have much preferred to pee on the ground but since there's no bushes between sites that option wasn't available. My husband ended up hopping on his bike and riding to a porta potty that was more out of the way and way less gross.