There’s really only two main spots in So Cal for surf riding, Oceanside and Pismo. (Pismo is really more central Cal) There are other spots but unless you’ve got a local to guide you, you probably won’t find them.
Here’s some info with Pros and Cons for both-
Oceanside
Located in North San Diego on a military base.
Average Water temp between 60-70 degrees
Average surf size 2-4+
Pros
Best quality surf, rarely gets windy
Has approx 16 mile stretch of beach which is pretty much deserted as beach access is restricted to general public
Easy access- you launch off your trailer on a paved ramp
Cons
Although you launch off your trailer on a paved ramp, you have to ride approx 2 miles of open ocean to get to the surf-(no big deal)
Accessable on your ski only (you cannot drive your car on the beach)
Pismo
Located in Central Cal on a State Park
Average Water temp between 50-60 degrees
Average surf size 4-6 (can get bigger)
Pros
You can drive your car and camp directly on the beach
You ride your ski directly in front of where you’re parked and you can take a break on the beach between rides
You can ride a motorcycle or quad on the beach when the surf is blown out
Cons
Usually windy with poor quality surf (The locals know the best times to ride)
You have to tote your ski through sand to launch-(no big deal)
Hope this helps. Its best to PM a local for some inside tips when you come into town