The Oregon Coast from Portland/Astoria down is spectacular, but be prepared for tons of Motor Home vacationers on that two lane ride, making it seem 'endless', at times. I would suggest balancing the scenic 2 laners with some I-5 time to keep things moving a bit.
In that area I would stay with 101 from Tillamook down to Newport (Mo's Seafood) then turn inland to the 5 and drop south to the Rogue River area where you can return to the coast for the crossing into California.
At that point either stay on 101 thru the Coast redwoods to SFC or jump east to the 5 for Mt Shasta, Mt Lassen, and some great fruits, nuts, and veggies and wine as you come down the upper Central Valley. There are tons of food stands at almost every exit on the 5.
Say Hi to Arnold in Sacramento (Or don't) then connect to SFC and the coast road south.
As you approach Monterey Bay area... Castroville
, Home of the Artichoke (in all forms) also in the center of the little town is the Central Texas BBQ
. Been there for decades, Good BBQ and if you have never enjoyed a Smoked Artichoke, you need to experience that.
In the same are is Gilroy
the famous GARLIC capital
. it may not be time for the annual festival, but there are plenty of stands and restaurants that feature the Garlic items in a wide variety.
Monterey is worth a stop. The Aquareum is outstanding and just walking along the shore watching the Otters feeding and playing in the Kelp Beds is worth the stop. Excellent seafood available on the Pier.
If you have never done the coast road south of Monterey to Morro Bay, then one time will be a good thing. After the lush green of Oregon, The semi-arid California Coast can be a bit of a let-down. The seaviews are wonderful, We saw Condors at a couple of turnout-overlooks that really were neat to watch.
Hurst Castle is interesting but not worth the admission price IMHO.
I've been away from LA too long to give up-to-date references. But this outline may assist you.