You can not really guess tongue weight. Typically it ranges from 8% to 14% depending on the design of the TT and how it is loaded. Hence, 12 or 13 percent is a good figure. The Ford towing guide uses 10%.
I have a forward storage compartment so almost all the weight I put in it is transferred to the tongue. Front Kitchen can may be different than front bath or front bedroom with under bed storage.
Some folk play around with weight in the TT. But unless you want to put your groceries in the linen closet and your linens in the pantry or your pots, pans and dishes in the front storage with your tools, jacks and camp gear above the sink; you are probably going to put stuff where it belongs.
You have a tow vehicle with a certain payload. You have stuff to put in that TV before you hook up the trailer. Whatever is left is available for tongue weigh.
If you choose 13% tongue weight you can calculate the weight of the TT you can carry.
Even then it is only a good guesstimate. The CAT scales are the eye opener.
Good Luck
