This is not a very good question. Commercial paper is made of cellulose (polymerized simple sugars) -- which is in the form of fibers. Usually from pine. These fibers have lots of space between them - from the point of view of an atom.
Note: different atoms have different diameters: ex: Carbon 1.54 x 10^-10 m
And paper comes in different weights (thicknesses). In the US there is 20lb paper, 24lb paper etc.
Care to refine your question? We have too many variables here to give a decent answer.
Also please note: Science deals with provable facts, not what 'you think'. The 'what I think' mentality about Science is the reason the internet is full of non-science, or politically motivated disinformation. We try to limit that here.
The question is "how many atoms thick is a sheet of paper".
Not how many atoms are actually aligned across the thickness of the paper.
So it seems that Nugatory's estimate makes perfect sense for the question asked.
Same as "how many fingers thick is a that brick". There are no fingers in the brick, for sure. And there are different types of fingers. But we can make an estimate.
Science is also about good estimates and order of magnitude calculations.