would it be possible to find a rv park and a beach nearby that avoids crowds? Or is really impossible to avoid people while rv beach camping in southern california
The further south you go, the busier the beaches. Once you get north of L.A. county, there are less crowded beaches. Above Santa Barbara it gets even less crowded.
There are many state park campgrounds on the beach BUT they are reserved 6 months in advance and almost impossible to get into. There is Huntington Beach City RV Camping that can be easier to get into. There is also Mission Bay in San Diego which has a few private campgounds. Good Luck