Refrigerator

Make and model of rig?
Make and model of refer?
Most RVs have a propane/electric refer. Many of use set the control to "auto". This allows the refer to automatically switch from 120 volt AC power to propane. While on the road refer will operate on propane with minimum danger. It will use a small amount of power from the 12 volt DC system.

Turned off? While in storage, days or week. traveling, 6-8 hours. or accidentally turned off.
How full is it, refrigerated cold foods, large thermal mass takes longer to cool down. How often is the fridge door opened? Ambient temps outside 40 or 60 or 90, at back of fridge and inside RV, air conditioning running.

Personally, if not running for 6 hours in daytime, fridge half full, temps around 85, I would not trust any perishables, throw the milk out.

Ken

You should have received brochures with your purchase. What is the refer model?

Shore power, batteries if residental refer or propane.

RV running? I assume it's a motor hope then? Having the engine running doesn't have that much to do with the refrigerator.
If you have a compressor style refrigerator it always runs on electricity. This can come from being plugged in, from the engine alternator, or from your battery.
If you have an absorption refrigerator then it always runs on heat. (I know, that doesn't make sense but it works.) The heat can come from burning propane, from an electric element powered by electricity from being plugged in, or from an electric element powered by your battery. The last choice is really not an option unless you have a very large battery and a very good charging system. An absorption refrigerator running on a battery uses A LOT of power. Your best option is to run it on propane when going down the road and on "shore power", electricity from being plugged in, when you are camped.
There are a few folks who have some sort of irrational fear of using the refrigerator on propane when they are driving. Don't worry about them. Probably 99% of RVers run it that way because that's the way the manufacturer designed it to be used.
If you have a new RV you likely have a compressor refrigerator but it's hard to say since you didn't give any details.

We need to know the make and model of your fridge to answer the question.

Your dealer really should have walked you through this.