My suggestion was to automate the process using Google Apps Script using an algorithm. You've not given a lot of details about what you actually want to do but for what you did give, Google Apps Script would let you automate the task.
Use Google Apps Script to open the document in Google Docs, read the number of pages that Google Docs renders, closes the document, then delets the document (optional).
w3schools is much improved over what it was originally, but it never became a top quality resource (even if you limited your search to "popular" and free). Also it's very web centric and OP is looking for something that's more fundamental.
I'm not sure that can be completed in 3 months by most people on their own. But I think it's a great option anyway. Probably best to use Emacs (Edwin) in doing so.
They're both based on Ubuntu which is based on Debian, so under the hood, they are largely the same and will continue to be for the foreseeable future even as Pop!_OS diverges from Ubuntu more each year (in a good way).
I think I've done that when I made one of my first posts on a Lemmy instance too. I don't know why you can't post a link and also specify an image for the post. Lemmy needs some refinement.
I thought I was legitimately missing something that everyone else was seeing and upvoting. I guess that wasn't the case.
Does Linkwarden fit your intended use?