Welcome to the North Coast. I have lived in the area since 1968 so I feel I know it pretty well. It is a wonderful place to visit and live although this year is and has been very wet. In fact raining as I write this.
As for camping. Closer to Eureka than Crescent City is Patricks Point State Park. This park is a few miles north of the scenic town of Trinidad. They have 124 sites and accommodate RVs up to 31 feet. There are many trails with vistas of the ocean and beaches to explore. Down this way there are also several Independent RV parks to which I can not speak about since I have not stayed at any of them. Going north from Patricks Point you will find an independent RV park called Elk Country RV Resort and Campground. This is a very popular place in the summer months. There is always a herd of elk around here throughout the year. There are also lagoons and beaches to explore with agate hunting in the surf zone at Dry Lagoon. Further north past Orick, there is Prarie Creek State and National Park Campground. 27 ft. is the maximum RV length here. There are many trails through the park among huge old growth trees. Also don't miss a trip to Fern Canyon. Heading north once again, I believe the next area with camping would be around the Klamath River. Here you will find several independent RV parks to chose from. North of the Klamath and into Crescent City there are also several independent RV resorts. If you happen to get into Brookings Oregon I can recommend Harris Beach State Park Campground. This is one of my favorite places. They can handle RVs to 55 feet. It has great ocean access and trails with great views.
Be advised that as of this writing, highway 101 between Willits and Garberville is closed due to a large rock slide. It has been closed for a week or 10 days now and I'm not sure when it is projected to be open.
Hope this helps and enjoy.
