It is a nice place, and I have stayed there. However it may have limited sites for a large RV. Also reservations may be need to say there. Check here: California Campgrounds and Camping - ReserveAmerica
. El Captian State Park is just slightly south has more parking, but is higher off the beach (on a bluff). Be aware the State Park system is charging hugh fees to camp. Like close to $50/nite at some parks, but at Refugio it starts at $35/nite. I like to find a "private" park near by and stay there, I find the cost are sometimes half what the state is charging.