Hi new rver,
Welcome to iRV2. Consider purchasing a supply of EternaBond ( RV Leak Repair Tapes & Sealants | EternaBond
). If you do not use it for this repair, it is something that is used by most RV owners, over time.
For me, I'd start at the roof and work my way down and forward/rearward on the coach to find the leak. You may not be able to see where the leak is actually coming from. One needs to do a couple of sealing sessions until the leak stops. What ever you did last was where water was entering the coach.
Since water takes the easiest route (not a straight line) the entry point may make no sense. Once you get the leak to stop, you'll know more about your RV than you ever thought you'd know.
Every opening and joint on my roof has EternaBond covering it.