Quake3World

While in mtplayer mode, i press ~ and the only thing that appears is: "unknown command" "+mlook"

do you know how can i display the console? and how can i type in it?

Edit your .cfg file with Wordpad. Check the key binds.

Thanks, but, how can i enable cheats in a server?

When you press ~ to access console, you need to type youre command with this before : / and you cant activate cheat on a pure server, insted you create youre own server and load map this way;
/devmap q3dm6, has a exemple