Also, you could try hosting a game with a name like, "noob needs help" or the like.  You might be surprised how many are willing to help someone with a good attitude.

Phiroxodaz, when you launch the game, click on ico button (2nd one down) to join multiplayer servers.

Good luck and Welcome!

Slackah had good advice.  Be gracious and friendly and accept your "nooby lumps".  Unfortunately this is a tough game to break into for online multiplayer PvP because most of the PvP people have been playing it PvP for a long time and almost all of the new people only play comp stomps with their friends (when they could be playing against each other instead).  It is kind of sad to see multiple groups of friends going against the AI when they could be challenging similar groups.

Most of the online PvP action is in 5v5 and 4v4 games.  I think people like them better since one single battle won't determine the entire outcome of a game and you can still find ways to help your team even if you personally are losing--your team itself can still win.  Oftentimes, especially at times when fewer PvP players are around, we need people to join and fill the games--that's your best bet.  You probably won't feel very welcome (nor particularly want to play in) games with the tag "skilled" in the title.