Just to make sure, you are plugged into a form of 120 volt shore power? The lights work off of 12 volt DC power ( either from the converter or batteries)
Fuses go to 12 volt things, breakers go to 120 volt things.
Is any of the 120 volt things working? Easy way to check, if equipped with microwave, are the lights on the microwave on?
If so, then you may just have a gfci tripped, which will kill the outlets downstream of it.
It's common to have at least two master GFCI outlets that you can reset. One is usually in the bathroom, and the other is in/near a kitchen area. Try to push the reset button on both these outlets to see if it restores power to the outlets.
If you don't have 120 volt power to the other appliances (microwave, air-conditioner, television, electrical outlets), then your problem may lie in the 120 volt power source/box, power cords, or breakers tripped. I would check all of these to make sure if you don't have 120 volt power in the trailer at all. First thing to check is a tripped breaker at the campground box, or a breaker inside your trailer. Not knowing your particular trailer, it's hard to say exactly where the power panel is in it. They are usually located near the floor somewhere, looking similar to this:
Read at your leisure to gain a better understanding of the 120 volt and 12 volt systems: