As pointed out diazr2, start by determining how much trailer you can actually pull. Don't go by the typical, my truck is rated to tow x pounds. That rating is artificially high. The weights you need to be concerned with are GVWR, GAWR and potentially GCWR. GVWR is the max weight your truck can carry, including passenger(s), fuel, cargo (either in bed, or in cab), weight of hitch, and tongue weight of trailer fully loaded.
Your max cargo capacity is on the yellow sticker on the drivers door jamb. It wil say something like max weight of all cargo, including passengers is "x".. That is your cargo capacity for that truck.
You need to take your weight, weight of gas (8 lbs per gallon... I think gas weight has to be considerd in cargo capacity.. others will chime in if Im wrong), weight of anything you will carry in the cab/bec and approx 100 lbs for the weight distribution hitch. Subtract that from the cargo capacity, and that tells you how much you have left for the tongue weight of the trailer.
To determine likely tongue weight, take the GVWR of the trailer (it will be on the front drivers side corner of trailer usually). The GVWR of the trailer is the max the trailer should weigh fully loaded. Take 15 percent of that value as an estimate of tongue weight. If this number, along with the calculation for weight of truck above, is equal to or less than the overall cargo capacity of the vehicle (as displayed on the yellow sticker), then it is a potential candidate for you to consider. If these numbers all end up exceeding the cargo capacity, then you have to move on to something smaller/lighter.
Hope it helps...
Mike
Im Mike Willoughby, and I approve this message.
2017 Ram 3500 CTD (aka FRAM)
2019 GrandDesign Reflection 367BHS