Questions on camping in California's National Parks

I'm planning a trip to California in 2026 coming from the east coast. I'm interested in staying in a couple of the national parks specifically Joshua Tree, Sequoia/Kings Canyon, Yosemite, and Redwood forest. It seems that most if not all of the campgrounds in these national park are boondocking only ( no hookups), I'm traveling in a 32' class C motorhome with a toad so I can do 3 days 4 days max with no hookups. I'm looking for info from anyone with experience in these national parks for help in best campgrounds to camp to explore the parks ect. I also have read some of the in-the-park campgrounds can be challenging to navigate to.

Any advice is appreciated.