101 north is a very pleasant drive. We did it multiple times with our 40' motorhome. People get confused with the coastal Hwy 1 and 101. They're two different roads. 101 is the one you want.
Your first stop could be Ancient Redwoods RV right in the heart of the big trees. Within a short distance are some very nice short, easy hiking trails amidst the big ones... very pretty area.
For Oregon I'd suggest making 3 stops of how many days you have available. Stop in the south, midway and the north. Then you can easily tour the surrounding areas.
We love Cape Blanco State Park and they don't take reservations. Plan to pull in around 2pm if you can (or earlier) and you'll get a site.
With our 40' MH we've also stayed at these state parks: Bullards Beach, Beverly Beach, Carl Washburne, Harris Beach and Fort Stevens on the north end. We love the state parks and since we had no schedule or time limits we pulled into them around noon and got sites without reservations - spring, summer, fall. Naturally, if you're on a timeframe that won't work for you but do try for Cape Blanco with no reservations. The beach is lovely with no people. The lighthouse tour is great. The sites are big.