Where does Mac store settings for applications?

Just looking for some Apple architecture clarification.  Hoping to get a better understanding of how the software and settings are stored/organized.  

I have a file that I made in pages containing login information for my convenience.  It is a chart of the login information that I use regularly, like an analog version of keychain I suppose.  I had a problem with pages changing, or autocorrecting the passwords and usernames that I was entering.  I wouldn’t always notice it when I first entered it and later, when I would go back to reference the sheet, it was wrong.  So I opted to turn off the setting where autocorrect wouldn’t change the passwords as I entered them.  

Since then, I have noticed that I don’t get the little red squiggley line telling me the spelling is off.  I wonder what other settings were changed in turning autocorrect off on my way to finding it, and would like to reset the settings in pages.  I haven’t found a way to do it, yet.

What I have tried.

• Creating a brand new user profile, opening pages, noting all the settings preferences, and setting the old user login the same.  No joy. 

• Next, I dragged the pages application to the trash, then emptied the trash and reinstalled pages only to find the settings exactly as they were when I deleted the program, still not working like would on a new machine or account.  No joy.  

It makes me wonder if resetting the computer to factory settings would even work.  Would the settings you had set previously, just be set to the way they were when you signed into apple ID?  Do the pages files themselves have the settings saved in the file to configure the program for that particular file when it is opened?  Are your applications settings saved in time machine?  Are they saved in your iCloud account?  Are they attached to your apple ID?  Thanks in advance! 

Steve