How can I play the multiplayer/online?

Hello there,
I've just downloaded from a site this game, & wanna play multiplayer, but I don't know how, because I've got no official key, and even I'll get one, I've seen on a video you need the console to connect on servers, like the classic counter-strike, old good times, any way, I don't know how to enable this console.
Please help me,
anticipated Thanks!