Newb question regarding max towing, GCWR, and WDH

thanks. I know the numbers i posted are all over the place, and that's what troubles me. Nothing seems to add up. My problem is that i don't have the trailer yet, and can only go by the numbers that Nissan gives me, and what the trailer manufacturer gives me. Worst case can i go pick up the trailer with just a basic ball hitch and find a weigh station somewhere? Not even sure where to find that in the Montreal area.

Thanks,