Distrobox for accessing any package from any other repo; including those belonging to other distros.

Bottles and virtual manager

Just figure out what you want to do. Its not like Windows where you need to run scrub scripts, or turn specific things on or off. It's very subjective.

Examples:

• are you in a laptop? You want specific tools for battery and performance tuning.
• are you gaming?
• are you working audio or video?

Just edit your comment and throw a few things out that you'd like to do, and you'll get a much more complete list of suggestions and tips.

Kdeconnect / gsconnect

gcc, an IDE, and make are my only must-haves. Those might not be your "must-haves" though.

KDE connect on both your PC and phone just use --no-install-recommends to avoid KDE bloat

cmus is great for music

mpv for videos, there are different extensions to automatically open YT videos with it.

beets for sorting music

nicotine plus for looking for music

syncthing

zathura

improving performance isn't easy if you feel like things are running smoothly, but there are a few laptop specific things like tlp that you could look into although I suspect that distro uses them out of the box

qalculate. It's a calculator. A good one, though. You can put in 2 * x = 5.5 or 100 inches to meters and get an answer, it loads fast, it keeps history, the arrow keys work and it has all the fancy scientific buttons you'd ever want too.

Cowsay

https://wiki.archlinux.org/title/general_recommendations

Take your pick.

installing random services with docker is pretty fun

hollywood

tree, screen, and wget have for a long time been the three packages I’ve always added on a fresh install.

Other packages are mainly connected to the use of the system at hand, like zellij, helix, and git on a development setup, or fish on any system where I do my doings mainly in a terminal och over ssh.

Also setup a bootable USB stick with a backup program like clonezilla to do full machine backups.

You'll get the hang of OS vs data backups later, but for now, do a full backup, play around installing / removing stuff and if you break it, you're back in business in no time

For gaming - https://github.com/sonic2kk/steamtinkerlaunch1 It bundles a few useful things as well like another suggestion: https://github.com/FeralInteractive/gamemode as well as quite a few others, tinker is especially useful if you want to mod too, making mod organizer 2 very easy to use, taking a lot out of the otherwise manual set up

Also in general, look for custom launchers, Genshin has a custom launcher, runescape as well, I believe gog does too. If you can't use foss at least use a better launcher.

for media honestly you can't beat VLC, but I run a plex server I typically use, for music I use strawberry, and for asmr desktop noise Blanket is a super cool package, and I like Cozy for audio-books.

Edit: Oh and for gaming I saw another comment recommending retroarch and I totally agree, retroarch works amazing on linux, so much better performance than I ever had emulating on windows before I switched.

vim

If you like music have a look at

• Picard
• Puddletag

Check out gamemode if you’re gaming, it should improve performance a little bit

For me after every install I immediately install media codecs but that's only because fedora doesn't ship with them by default.

Is there a thing that you do?

Are you looking to sysadmin or dev or something else?

Libreoffice. Librewolf but then I deal with students.. ymmv

What is a "must have" depends on your use case, personal preferences, and the shortcomings of your distro's default configuration (I've never used Cachy so I don't know what's missing).

For myself, I usually end up installing VLC and Strawberry Media Player, since the media players most distros come with aren't as good. On non-GNOME distros I tend to install GNOME Disks as it's the least painful to use of the GUI partitioning tools I have used. My preferred rich text format is Markdown, for which I use ghostwriter. I also usually install a few FOSS games to pass the time with - my favorites are Freedoom, SuperTux, SuperTuxKart, and Xonotic - and RetroArch for emulation.

KeePassXC or keepass2, VLC, mplayer, mpv, qmmp, gimp, qtqr

on X: xdotool, xmacro

on Wayland: ydotool

free cool games (some not in repos, some snaps): OpenTyrian, AstroMenace, warzone2100, Card-Forge Java MTG Simulator, Heroes Forge, Spiral Knights (Very old; May need Java 64bit tinkering; Also on Steam)