Explanatory video on how to set scale in Paper Space (Layout).

Simple:
1st, be aware that the standard unit of AutoCad is the millimeter (try printing a 100x100 square in a 1: 1 scale and it will come out in 10cm X 10cm, that is, 100mm X 100mm.

2nd choose your unit when drawing in AutoCad. Simply, for example, make a line of "10" saying that it is 10 meters.

3rd when configuring the scale in the zoom of your vielport, in a scale 1: 100, for example, play in the zoom 1000 / 100XP, in other words, 1000 millimeters = 1 meter DIVIDED by 100.
If you were working in centimeters, just put 10 / 100XP, that is, 10 millimeters-1 centimeter DIVIDED by 100.

And so on ... =)