You’ve chosen an immutable distro based on rpm-ostree. If you want to install a program/application/app then flatpak is the way.
Heroic Launcher works great for installing GOG/Epic games but if you want to install a game or other program from an offline installer then I still fall back to Lutris.

For more in-depth read up on rpm-ostree and flatpak

A lot of games are going to work without you having to do anything and some will need some tinkering. In that case, https://www.protondb.com/ will be your best friend, telling you exactly what you need to do to get things running.

That being said, some games simply can’t be run under Linux. They might work in the future as compatibility improves but some won’t. If it’s an issue for you, you might want to dual boot windows as a workaround.

Use alternativeto.net … not necessarily for just Windows programs alternatives; but it is also great for looking at popular utilities for any task in Linux.

Some programs I use a lot were not suggested anywhere else (e.g. Pluma as a basic text editor and Pinta for basic image editing).

Execute “ujust” and marvel at what’s possible right out of the box. If you used KDE check out some simple tips on how to configure cool windows effects. A little wobble makes all the difference. Browse the apps you can install, there are some pretty neat things in there you probably never heard of before.

And don’t forget: once you got the things you want working, let the system fade into the background. No need to constantly tinker with your distribution unless you enjoy it.