There's good camping at Flint Ridge campground on the hillside just above the parking pull out. No camping on the beach.
I haven't been in a while, so I can't comment on sand levels or condition of the trail down to the beach.. which goes straight down from parking area and can be overgrown early in the season.
I know the Yurok have made a claim to this whole section of beach, but last I heard it wasn't resolved with the National Park service. I've never had a problem, but I've been told: don't go any further north than the group of boulders marked "Lost Rock boulders" (see photo).
There's great climbing south of Flint Rock too, for quite a distance.
And watch the tides so you don't get trapped in an alcove somewhere. Enjoy!