Santa Rosa Fairgrounds (accepts various camp cards - Escapees/Passport America & I believe Good Sam/FMCA) or Napa Valley Expo are reasonable for the San Francisco area.
I'd recommend you drive on 101 into Oregon. It's a gorgeous drive. Ancient Redwood RV in Redcrest, right on 101 is a great place. It can accommodate big rigs and it's right in the heart of the big trees. Spend at least 2-3 days and do some short hikes to see them.
101 takes you into Oregon and the whole shoreline is dotted with state parks and you can't go wrong on any of them. Without reservations, pull in early morning. It's the only state we've been where so much prime coastal land is devoted to preserving it for future generations. It's wonderful.
Bend - You might want to continue up 101 and the Oregon coast and cross the bridge at Astoria and pick up the Washington Hwy 4 into Kelso and I-5. It's a good crossing. We then use the 205 east bypass. It's not an easy city to get through - lots of traffic. You could then pick up Hwy 26 at Sandy and take it into Bend for your fishing. Tumalo State Park is there and further south is LaPine State Park.
Crater Lake: We've stayed at Joseph H. Steward State Rec Area on Hwy 62 near Prospect and also Collier Memorial State Park on 97 just north of Klamath Falls. Both are ideal for touring Crater. Crater also has a campground but not sure of size restrictions.
Have a good trip!