Thanks one and all for the thoughts and suggestions.
Problem solved. I pushed in on the door near the lock as I was (gently) turning. I was able to get it open.
As I had the door open, I was fiddling back and forth with the locking mechanism so see what was going on. There is a bolt that holds the lock on place on the inside. As I was turning the key, I noticed that the bolt turned slightly indicating it was loose. I hand tightened it, and that forced the entire mechanism latch away from the door. In other words it could now swing more freely from unlock to lock and then back again as it latched shut.
Since I need a trip to the hardware store to replace my sheared key, I will make sure to get some graphite lube (already have a nice can of WD40), and put it around all of my bin locks. Sounds like a good maintenance procedure to do from time to time anyway.
Again, I really appreciate you all helping out a newbie. Looking forward to many years with my new RV.
See you all out on the road!!