I store my rv next to my house on a 15amp circuit. I have an electric heater running non stop, a few lights, the fridge on electric (cold beers at all times) and when im in there tinkering i have the tv on. This is pretty much the exact limit. Sometimes i run the water and the pump trips the breaker. If im tinkering during the summer I’ll start the generator and turn on the ac because i sweat like shaq at the foul line.
If you overdo it you’ll just trip the breaker. Not a big deal. Depending on how long you are there, you’ll learn precisely what you can run without tripping it.