Right now I need ideas on what to look for and how to fix it.
Wood should feel like wood...hard. If its stained, discolored or soft , that is a sign of water intrusion.
Sign onto 'youtube' ask 'how to repair rv roof leaks'
'how to repair rot in an rv'
you will see visuals of what to look for, what tools to use.
Ideas of a roof repair/fix are rolling in but that may not be your only issue.
***Water will seek its lowest point and settle in places possibly not anywhere near the roof.
This is especially true if your rig was parked, sitting in the same position for long periods of time while it was leaking. That would allow leaking water to travel and pool in areas to which the rig was parked possibly off level.
You could try to peel up a 'tiny bit' of flooring or lift carpeting along the floor edges of certain areas to see if its dry, wet, damp or moldy. The floor should be solid not soft or spongy.
You could open cabinets and drawers to look inside for water stain evidence and discoloration on the 'wood surfaces'.
*** Use a flashlight and use your nose. Sometimes you can smell dampness inside a cabinet before you can see it and a flashlight is certainly your best tool for inspections of dark interior places.