When we started RVing, about 15 years ago, we did our first trip to the west coast. It wasn't quite coast to coast but Vermont to the west coast. We decided we would make no sightseeing stops east of the Mississippi. We would save that for when we got older. That was a trip to Alaska.
West to Montana, then make a right turn and up the Alaska Highway. Spent about 6 weeks in Alaska then came back home. Had a wonderful trip, saw many things and spent the longest day of the year, June 21, in Fairbanks, our most northerly stop. The sun set briefly but it never got dark.
2 years later we went to Fort Worth TX (100+ degrees), then to Yellowstone where it snowed, then on to the Northern California coast stopping at Crater Lake and many other spots. From California, north along the coast to Vancouver, BC, with many, many stops along the way.
2 more years later we went to the San Francisco area then returned thru the south west.
Three great trips to the west coast. Saw many wonderful sights.
Hope you have as great success and enjoy it as much as we did.