If you can find a package that works with your package manager, you can install most software with the manager or use a flatpack, but even install scripts are very easy once you learn to cd into the folder. You should really ask chatGPT to help you when you run into issues. It really helps. You can just copy and paste console output when you get errors and it will guide you through it.

Bazzite also comes with a built in onscreen keyboard and many things have it under the accessibility options. I run on screen keyboards on all my Linux devices for the occasional need, I also bought a pocket sized mini keyboard that is Bluetooth.