What are the fun ways to learn and master the file management system in Linux ?

Are you referring to how to manipulate files, or more what the various files and folders do?

EDIT, now that I’m typing on a keyboard (connected to a linux PC, obviously), and not on a phone:

Depends entirely on your definition of fun, really, but the way I learnt it was basically by breaking stuff, sometimes intentionally:

• Poking/editing files in /etc to see what happened
• read and write data from/to files in /dev (Careful, these are devicenodes. This is an easy way of overwriting your partition table). As far as I can see, /dev/dsp doesn’t exist anymore, but you could cat a .wav file to it and it’d play through the soundcard. I gues modern sound pipelines are a lot more sophisticated hence why I can’t find it
• Play around with redirects and pipes: > >> 2>&1 | 1>/dev/null
• Get comfortable with file permissions and how to use them. I had many users on this server I had, and I liked to (ab)use the group bit to grant access to various things.
• Poke every binary in /bin and /sbin to see what they do

:wq

https://github.com/phyver/GameShell

https://linuxupskillchallenge.org/

There’s the program that makes it 3d like in Jurassic park. 3dfsb

Linux from scratch.

Install Arch

Bunch of sites out there like: https://www.learncmd.io/

Play hacknet

You can combine practicing navigating the filesystem along with a game like rpg-cli !

You can think of it as basically “programs”, “more programs”, “stuff”, “gubbins”, “misc” and “other”.