Break it down into a hit list of jobs to do. start with safety items first. Then fix the structure items like frame and floor rot. Then make it comfortable ie all interior stuff. Last make it yours with all your personal touches. If possible try to camp in it along the way.
When I first got my 1969 AS Sovereign
. I fixed all the trailer lights made sure it was safe to tow then camped in it right away 3 or 4 times. Then I parked it for the winter and gutted the front half. I repaired all the floor rot put new flooring. Then I fixed all the plumbing. Last I put back and restored all the kitchen and living room. Next year I will tear out the bathroom and restore that but I WILL CAMP IN IT THIS SUMMER. Restored bathroom or not.