Congrats on retirement first.
This would be a list of a few of our favorites.
CA- Yosemite is top of our list, Sacramento has an awesome railroad museum. Coast redwoods.
OR- drive the coast. Astoria has a great maritime museum as well as fort Stevens and fort Clatsop. The Portland zoo is great as well as Oregon museum of science and industry where you can tour a submarine. The Columbia river gorge is also worth a look.
WA- Mt St Helens. Olympic nat. pk. We stayed in Port Angeles and went to Hurricane ridge. We also took the passenger ferry over to Victoria BC for the day.
There are so many great places to visit you can't possibly see them all. After I retired we took nine months to tour the USA and only scratched the surface.
Have a great trip.