Would you happen to know a good way for me to learn more about Linux, and how to put it to good use from a beginner’s perspective?
The new terminology will be never ending. The unix philosophy is to make small tools that do one thing really well (vs a single large monolithic OS that does a ton of things half decently), so every single component in and around Linux has a name, its own set of maintainers, and pages of documentation you could spend hours to months learning (depending on the tool).
On top of that, the open source ecosystem isn’t centralized, there’s no CEO telling everyone the one way to do things. Instead, everyone is free to build whatever they want according to whatever design patterns they choose. This is a blessing and a curse. There are packages that work nicely with other packages, and there are many you probably shouldn’t waste your time with.
All this is to say, I recommend always having a goal in mind when digging into Linux, and get good at skimming new terminology that you think is relevant to your goal. Be able to quickly understand what something does and how it’s used, but avoid going down the rabbit hole for every little thing.
That’s not to say you shouldn’t satisfy your curiosity, just know that you can be overwhelmed quickly if you don’t know how to tune out the noise. Being goal oriented helps me stay on task as I learn.
Good luck!
to answer your question KDE is not arch. Linux has a bunch of distros, you can think of one as a collection of packages. some distros want to do things one way some want to do it others.
the biggest difference between distros for most users are mostly desktop environments and package managers. KDE is the desktop enrollment, there are many others that you could also use, like gnome, or use none at all and only use the terminal. the package manager is how you get new packages and update the ones you already have. examples are apt and pacman.
you can make any distro work like another by installing the same packages, although this may not always be the easiest to do. an easy way to change your experience with Linux is to try a different desktop environment, you can run multiple on the same distro and switch between them, see what you like.
Until now, I had been under the impression that KDE was just arch Linux itself.
Like others have already noted, KDE Plasma^[1]^ is widely available and thus not only limited to Arch Linux. Heck, the same applies to 99% of the available software on Linux; universal package managers^[2]^ have been vital to this.
Would you happen to know a good way for me to learn more about Linux, and how to put it to good use from a beginner’s perspective?
As you already own a Steam Deck, I assume you want to look into how you may improve your mileage out of it. Others have already noted how you may do so for more traditional systems. But the way Linux is utilized on the Steam Deck is rather unique. It utilizes immutability^[3]^ (i.e. the inability to make certain (permanent) changes) which makes it rather harsh to change certain parts of the system; SteamOS’ implementation might even require you to redo some of these changes every so often… which is probably not what you were expecting. To circumvent this, perhaps it’s worth exploring other SteamOS-like distributions that are more friendly towards tinkerers. There are many to choose from; perhaps this breakdown may help you with making an informed decision (even if it’s found on a page dedicated to the Legion Go).