You will need to know what your power requirements are to find the right one for you. Generators are usually rated in Watts (ie. 5500, 4000, 2500, etc), and you will need to know the maximum number of Watts your trailer will require. Most appliances will have either the wattage or the amp draw on a label somewhere, or possibly in the literature. Remember that Watts=ampsXvolts. Your camper will have a 120 volt A/C system, so you should be able to do the math for the appliances you need/want to run simultaneously, then buy a generator with a continuous output greater than or equal to your needs. Don't forget, appliances with large motors (ie. Air conditioners) have a "starting load" that can consume quite a bit more power when firing up then they do during operation. My 15,000 BTU main A/C unit draws 13 amps when running, but it's starting load is 18 amps. Once you've picked your generator your 3 prong shore power cord will plug right into it (do check that the generator has the proper recepticle for your power cord). I've only ever had manufacturer installed generator sets, so I'm sure someone will chime in with a greater wealth of knowledge, but hopefully this will get you started. Oh, and since your lights are going to be 12 volt run from your converter, be sure to find and add the amp draw for your converter as well, so that you will have sufficient A/C power to provide for all your lights and to charge your battery(ies).
2013 Voltage 3895
2011 Ford F-350 DRW w/ Firestone airbags and heavy duty compressor, Edge Insight CTS, Curt Q24