Welcome!!!
Best thing to do is start by posting what your tow vehicle is, the area you plan on towing- flat lands, or mountains.... and many familiar with the smaller trailers can help guide you to what would be a good fit weight wise. Start searching the manufactures websites to try to find a trailer. Also, is there a camper show near you anytime soon?
If you look at a Jayco, then you want what they call the Thermal Pkg. other trailers have a similar option, which is extra insulation, heated and enclosed underbelly or possibly heated holding tanks.
Do you plan on dry camping? Most trailers the dealer includes a single, 12v battery with the trailer as part of the start up. If you plan on being off the grid, many have added a second battery, or even swapped 2 golf car batteries in place of the standard 12v battery.