Welcome to the club!
A 12 Pro-4X, congrats! Hope to see some pictures soon
As far as towing goes, I've gotten to pull around several trailers and have a few observations I can share with you. First off the size of the trailer is really important to keep in mind. I tow around some ATVs on a 12 foot trailer and have very few issues with it. Once you get past that to the 16-18 foot range things start getting a little awkward. The Xterra has a short wheelbase so keeping a long trailer under control can be challenging. And an 18 foot trailer isn't bad to me, I just know I can feel it pulling to the sides at high speed and it makes me a little nervous when driving. I really wouldn't recommend pulling a 20+ foot trailer. Power's not the issue, but at the very least you'd need a trailer brake controller.
Hope that helps a bit