this is a little guide for installing quake 3 on modern systems
Content Table
You have two options to get the game files
You can also search other places (like archive.org)
I'd recommend you to install Quake3e but you can also try ioquake3
Just extract the file and drop it to the game directory
Here are some tweaks that you can put in your baseq3/q3config.cfg
FPS for multiplayer is limited to 120, but you can still change the single-player max fps