Also checkout Heroic Launcher, Epic gives free games every week, there’s plenty of fun to have with those too.

Since OP is new to linux I’ll just add this in case it’s helpful.

To edit a file owned by root (super account) you can use sudoedit /etc/apt/sources.list or alternatively sudo nano /etc/apt/sources.list in a terminal.

In the editor save by using the key combo Ctrl+S and exit with Ctrl+X.

Commenting is adding a # in front of the line.

so the file should look like something like this

# deb cdrom:[Debian GNU/Linux 11.5.0 _Bullseye_ - Official amd64 NETINST 20220910-10:38]/ bullseye main