If you belong to Thousand Trails Resorts, they have many RV Resorts off 101. I would say there are at least five between Crescent city and Seaside, Oregon. One at Florence, Oregon, Whalers Rest in Newport, Oregon. Pacific City rv resort and Seaside rv resort all by the Pacific ocean within walking distance to the beaches. Sea lion Caves just north of Pacific city is very interesting place to visit. And if you are headed south on 101 there are the Giant Redwoods which is a must.
Lots of other RV parks along 101 open to the public. I would stay away from state parks if you have a coach longer then thirty two feet.