Welcome to the forum.
You do not lube the slide you can wax or use
303 Protector on slide side walls or the rubber seals around the slide and if its having problems getting up the ramp make a
very small adjustment to the pot on the
control unit.
Unit maybe in the hutch cabinet or under the kitchen cabinet in most cases.
Here is a
Brochure and
Owners Guide for you.
Below in my signature are links to many more for your Newmar.
Enjoy the forum and safe travels.