In that case, try practicing with the AI first. Kind of like getting the feel of the game. And like I said, try playing with someone you know. The tendency is when you play with someone you know, you'll be more comfortable, confident and therefore focused.
And remember, just remember not to bottle up emotions. Release it. And feel the groove of the game; the more you feel it, the more confident and focused you can be. Kind of like an IdrA situation (pissed = worse, confident = better).