Scotty! I changed my oil and filter and followed the instructions in my manual to fill up the oil and the filter with the correct amount of fluid, running it for a minute, and letting it cool down, it’s totally dry when I pull the dipstick? What am I doing wrong? I drive a 2018 Honda Civic Sedan with a 2.0 L engine and when changing the oil and filter it says to put 3.7 quarts so I put exactly that.
The Amsoil website says it's supposed to take 4.4 quarts.
Do you see the problem?

true but he wrote that the dipstics was totaly dry, with 3.7 filled it should not. So 3 things can be wrong :
1. Wrong oil level
2. Wrong dipstic
3. Wrong oil pan.
He needs to check exactly everything bit by bit
I doubt it. He just needs to put another qt of oil in it.
checked it too it gets weird, check that you have the right manual for the right engine, here is 4.4 quarts
https://www.motivxtools.com/blogs/guides-and-tutorials/2016-2018-honda-civic-oil-change-guide
https://www.amsoil.com/lookup/auto-and-light-truck/2018/honda/civic/2-0l-4-cyl-engine-code-k20c2-6/
Here is 5.7 quarts
And check your dipstick serial number if it has one.
It is 4.4 quarts.
Royal Purple 4.4 to 5.7
https://royalpurple.lubricantadvisor.com/eng/Recommendation/b5d256efcc2d07d5a56de600e1a67ea7