There should have been a cord to plug in somewhere at one time. Somebody has stolen it. Take apart the box where the screw in fuse is located and see if you can find where the cord originally was. Then you will have to replace it with a new cord. You should find someone that knows about 110 volt power for this to be on the safe side. All the cord will do is let your outlet inside the trailer work. The lights most likely were run from 12 volt battery power. ( like a car battery) There should be a place to put a battery and the wires to hook it up. If not someone stole them too sorry to say. The battery was probably mounted on the hitch but, not necessarily for sure. I once had a old trailer that had the battery mounted in a enclosed box inside the trailer with a access door to the outside to pull the battery in and out of.
