This is my favorite interior cleaner, it just smells "clean".. if that makes sense:
https://www.amazon.com/Chemical-Guys-SPI22016-Protectant-Fluid_Ounces/dp/B071ZTPRJL/
Shine Supply for compounds/waxes.
Welcome @Cazual - Oddly, we've had plenty of problem posts here but nothing really that says the trans is a bad one. Granted, sometimes mechanical things just break!
Welcome! I would have the dealer pull the service records and see what kind of "life" the truck has had... also, read around the forums here as we've got plenty of info for you to help you with your decision.