Paul, one of my favorite places in the world is the Morro Dunes Campground
in Morro Bay almost in the shadow of Morro Rock. It's not too far off 101.
There's some great camping along the Mendocino Coast as well. Fort Bragg, CA offers some great scenery, good accommodations and excellent food. MacKerricher State Park
is beautiful, and the Harbor RV Park is right at the foot of the bridge over Noyo Harbor and also has ocean views. Cap'n Flint's Seafood restaurant in Noyo Harbor is a must in Fort Bragg. Cap'n Flint is an old friend who used to occasionally sail with us on ClearLake when we lived there, and his seafood is second to none.
After you get south of Morro Bay, there are some state beaches that you'll pass along the way. You pretty much see what you get as you drive by with those.
After you turn left at LA and head for the desert, here is a site that may help you find someplace along I-10: Camping along California I-10
I don't have any experience with any of these places...
Have a great trip!