A lot of people do it with paint in modern fresh colors. Pale gray is the current favored neutral for walls. White cabinets, gray/black/white patterned fabrics. That sounds drab, but all it takes is a little pop of bright color in the fabric, plus a few accessories like cushions or curtains to pick up the same or compatible brights.
From what I've read, surface prep is critical to a good paint job. Re-glue any loose trim strips or wallpaper. You should be able to get those beautiful (not) borders off pretty easily.
Wash with a solution of TSP to remove dirt and grease. Sand very lightly with something like 100 grit paper. Then wash again to remove sanding dust and more dirt. Use 2 coats of primer, then probably 2 coats of the decor color.
I've done a fair amount of reading---if you google "redecorating RV" you will get lots of info. Also, make a Pinterest account to keep track of ideas from other sites. (Your wife or granddaughter can show you how to do that, LOL.)
Single empty-nester in Middle TN, sometimes with a friend or grandchild on board