The below 3 tools are free and will assist you in organization.
This tool provides tabbed file exploring, which is essential. There are other free apps out there, do some research.
https://www.zabkat.com/x2lite.htm
Find files with this tool
https://www.mythicsoft.com/filelocatorlite/download/
Use mp3tag to create order out of music collections in disarray. Hint, mp3tag's file renaming functions allow you to move files and create directory structures that didn't exist before, all based on music file metadata.
>Because shifting through the Economics folder for the book would take a long time and I can simply go through the Very Important folder and read the book.
I get past this problem two ways. One, is by dragging file shortcuts to "favorites" directories. The other is by prefixing very important files with a numeric sorting prefix, so they float to the top of the file manager, such as
dir.books...
..sub.dir.sociology
......015 Very Important Book.epub
......030 Important Book.epub
......090 Interesting Book.epub
......Book.epub
......Book.epub
.........etc
Music is stored by genre subdirs then musician/band name, such as...
Music
...Rock.A.F
......Aerosmith
.........Album#1
.........Album#2
...Rock.G.M
...Rock.N.R
etc...
explorer^2 by Zabkat is an amazing Windows Explorer replacement that has dual panes and tabs. It has been my go-to file explorer for at least the last 10 years.
https://www.zabkat.com/x2lite.htm
I have been using the paid version for a while, but the lite version is really very good.