My spouse and I are looking at purchasing our first RV, he grew up camping, I did not.... We have a 2019 Chevy Silverado 6.2L with max trailering, manufacturers tow rating of 12,200 pounds and are ...
You need to use the payload rating of your particular truck. Look at the yellow tire loading sticker on the door jamb of the truck. It will say something like "weight of occupants and cargo should not exceed xxxx lb".
Now add up the weight of passengers, cargo, AND the tongue weight of the trailer. Not the dry brochure tongue weight, use 13% of the expected loaded weight of the trailer. That total should be LESS that the payload capacity shown on the door sticker.