Welcome and congrats on the tt!!!
As mentioned, load your truck with all the dogs, and go weigh it. Any scale would work, but a CAT Scale will give you seperate front and rear axle weights. Now look in the drivers door jamb for the gvwr of your truck. Subtract the actual weight from the gvwr and that is what is left for the tt tw and wdh, and possibly any additional cargo you may put in the truck bed.... The available payload of your truck is going to be the challenge. As mentioned, all occupants, cargo (including any accessories added after the truck was built: your truck cap for example), the wdh, and the tt tw all count toward the payload of the truck. Follow my signature links for a CAT Scale how to and if I recall correctly a link to a scale locator.
Look in the glove box for the sticker with all the codes in them. Look up GM axle ratio codes, and see what axle ratio you have. As long as you have at least the 3.42 gearing, you should be good to go power wise due to having a 6spd trans. Just know that the newer motors like to rev to make the needed power. So don't expect to only run the motor at 2k rpm up a hill, it may be more like 3-4K rpm depending on how steep of a hill. If you have the 3.08's, well, your truck may pull the trailer but not sure how well it may do. You may even be near the max tow rating if not over if you have the 3.08's.
If you don't have one, get a good wdh with integrated sway control. The Reese Dual Cam, Reese SC, and the Equal-I-Zer 4 way system are very good for the money.
Good luck!
