Universal Tow Wiring help needed

[arcteryx33]

I did not get my truck delivered with the tow pack installed which is unfortunate but was able to get the received from the dealer. I would like to add a simple 7pin/4pin combo unit to the blank hole under the bumper but need help with the wiring. I was planning on using a powered or non-powered universal kit as all I really plan on towing is a light weight folding garden trailer with LED lights. Any help would be greatly appreciated!