bought, a trailer with no manual

Manuals for RV's are generally useless. Go around to each appliance (furnace, A/C, Fridge, water heater,etc) and write down the brand name and model number/serial number. Most manuals for those are readily available online from the various manufacturers. Most stuff, like window gear boxes, you will have to use your imagination and skills. Most of the lights will work off a charged 12 volt battery. The electrical plugs, microwave, A/C will require you be be plugged into a power pole to work. Good luck and keep asking questions as things arise.