Welcome to the forum!
There are several different types of slide out systems. Mine is rack and pinion, and requires very little maintenance. I just keep the teeth on the arms clean, free of rust and dirt. I do use a small amount of dry lube spray on the drive teeth, but not often. Other than that, I keep the slide wipers, and seals clean, also use a little slide seal conditioner on them, to keep them soft. A little baby power on the wipers keeps them sliding easier on the sides. I use ProtectAll on the slide outside walls also, including the windows and frames, to keep them slick.
While moving large slide in/out, it seems to operate best, with door open, to allow air displacement.
New trailer is a big step up from your PUP, hope you enjoy it!
Jerry