I took my son up to Redwoods National Park over Thanksgiving in 2017. We flew into Oakland, spent the night, and then started driving up the next day.
We did the redwood highway, searched out the Paradox tree (5th tallest in world, will be #1 in 2031) and wandered around in Humboldt Redwoods State Park, visited Confusion Hill (gravity house), the one log home, the drive-thru redwoods (most on private property now), and hiked around the National Park once we got there. Be sure to take some wading boots and hike Fern Canyon. We made it all the way up to Trees of Mystery.
We stayed in Arcata and then at the Benbow Inn on our way south. We stopped in Ferndale For coffee for me, which was a cool town.
FWIW, my kid loved the show Gravity Falls at the time and this trip had a lot of the things that inspired the show.