I should add the best scenery is the Oregon coast but you may not have time to do it justice.
Near Astoria we stayed at the KOA though there is a state park across the road. That is an interesting area to stay. Drive on the beach and watch the fishermen casting for crabs, the maritime museum and the tower.
Near Coos Bay stayed at Oceanside RV park, beach very short walk, also state park nearby.
Tillamook we stayed at Tillamook Bay RV park, decent enough so took in the cheese factory. Up at Garibaldi check out the steam trains. In Bay city take in the Pacific Oyster restaurant out on a pier.
The up in Washington I could live in Port Townsend.