You can do almost anything in So. Cal. so you need to be precise about what you want to do.
However, a serious warning...
The thing you will be doing most is driving. Blah, Blah, Blah the traffic. NO! Seriously, listen up.
Do not underestimate the traffic, there. Driving in traffic is LIFE in So. Cal. Whatever you expect, double it, then double it again, you still don't get it. Do not expect to go from one major attraction to another after staying late into the night. For example, do not go to Magic Mountain or Disneyland, and expect to go back to a hotel, shower, sleep, and then wake up early and go to the another theme park because it won't happen. My advice, plan out your trip, and post it here, people can give you an idea of the trouble spots on your travel routes and times. You think I'm joking, but seriously, unless you live there, you can't understand the traffic. You THINK you get it, but really, no matter how prepared you think you are, you're not until you actually experience it, it's mind warping if you end up on the wrong freeway at the wrong time.
A 20 mile drive, depending on the time of day and even the time of year, can take 20 minutes or 3 hours, and this is with no accidents. And then there are highways where if you are only doing 80mph, you better be in the slow lane (far right).
OH...
And if you are not used to aggressive driving, rent a big SUV, not a commuter car. So. Cal. drivers are driving bullies and will literally try and run you over if you get in their way (STAY OUT OF THE WAY!). The bigger or more expensive the car, the bigger bully they can/will be, that big Mercedes is less likely to cut you off if you are in a big SUV, but isn't going to think twice about doing it to that tiny Kia and if you are not used to this sort of thing it will probably scare the hell out of you.