I drove from Southern California through the redwoods and up the Oregon coast to Cannon Beach about 9 months ago. It's really beautiful!
Hwy 101 through the redwoods had some wash outs from previous heavy rain a couple of years ago but most of it had been repaired. Oregon has excellent roads in most areas of the coast, Tillamook the roads were a little rougher but still considerably better than Southern California or Bay Area roads. They may have repaved those by now, they were working on the roads all along the coast of Oregon. Northern California Hwy 1 had a lot of washouts 2 years ago, rough roads.
There are lots of great hikes through the redwoods, long or short, near roads or off the beaten path. The rangers in Crescent City are very helpful, when I told them I was in a RV they told me the best places to park (fairly level parking in the shade) and the hikes in those areas. This last time I specifically wanted to see Fern Canyon because I didn't have time before (between Orick and Crescent City), you can't drive a RV to it, we rented a car and then washed the car because it was filthy (it's several miles of dirt road and you have to cross a creek or two).
It's easy to find free tourist magazines that lists things to see and do, Mile-by-Mile Guide (Oregon and parts of California and Washington) and 101 Things to Do (parts of Oregon and California). They are pretty helpful, I've used them for 2 trips so far. Oregon visitor centers are very helpful too.
I hope this helps.