Multiplayer will not load or creat games

[STASHMAN3000]

Hey guys I just bought this game a few days ago and have already beaten the career mode and wanted to see how the online play was.

Turns out that I can't do that because my game will not load any internet games nor will it let me make any games.

when I try to make one it goes to a please wait screen and stays there. The only thing I can click on is the cancel button which takes me back to the menu obviously.

I bought the game on STEAM and they game me a CD-KEY for it.
If this is my problem then where do I enter the CD-KEY. I looked all over the place.

Thanks for any help