I did my PPL training in Southern California. Great place to fly.
I'd recommend in So Cal:
Big Bear - The airfield is at about 8,500ft, approach over a huge lake with a space telescope. Beware of density altitude, tempurates when I was there in May were as high as 20C up there!
Bishop/Mammouth - In the Sierra Nevada mountains. Not difficult to find, just head north between the two mountain ranges avoiding restricted airspace. Makes for some great pictures. Rent a car in the town and go up the mountains. Density altitude is an issue here again.
Riverside - Has a nice resturant.
Ontario - Land behind a B737 and before an A330. Its a major airfield in Class C thats very busy which makes it a challenge.
Catalina - On an island off the coast from the LA area.
Santa Barbara - Another large airport in Class C. Has a good resturant, but can't remember what its called.
Fly a VFR corridor route over LAX, just for the hell of it.
Have fun, wish I could go with you!