New to RV's: Need to Run Maintenance on 99 Mini Winnie

Put a tarp over it to stop further water intrusion. Apply heat and fans inside to help dry it out- might consider dehumidifiers as well. Carefully take apart the wet panels to determine the extent of the damage. If the damage isn't too bad and repairable consider having the rig pressure tested (about $125) which should identify all the "leaks" - easiest way to identify the source of the leak(s).