Boy, that's quite a stretch to try to stay around: there's approximately 500 miles between Crescent City and Santa Cruz. In fact, Crescent City is way up there! There are some private campgrounds open. For example, one of the KOA near Santa Cruz is open (
https://koa.com/campgrounds/santa-cruz-north/). After you find a few private campgrounds that are open in the areas you would like to go, then you need to check the beaches. Many state beach parks are closed. However, there are many surf breaks that are not in state parks. I'm pretty sure the County of Santa Cruz banned all surfing. Maybe the best thing is to find where it is possible to surf. Try this newspaper item:
https://www.mercurynews.com/2020/03/23/ ... king-lots/ I think surfing is allowed at Caspar Cove in Mendocino County. If so, there's at least one RV park there that's open. Although not either of the two places you mentioned, it's a wonderful place to camp, surf, and go slow. It's a safe place for kids, too.