Congrats on the new camper! RVing is the best way to travel!
As for places to see and stay along the way, we followed the Oregon Trail (most of it) in 2012. There is a museum on I-80 just east of Kearney, NE which is very interesting. When I say "on" I-80, I literally mean on it. It is like an overpass, only you have to get off at Kearney and travel east to see it. Depending on the route you take, Mount Rainier is very nice. The tour of underground Seattle is awesome. Just a couple of things we saw along the way. Have a great trip!
2012 Cruiser Sahara 330SS
2015 F250 Super Duty diesel