Please refer to the "stickied" threads at the top of this technical forum.
There is some reading, understanding, and configuring that may need to be done in order to have a problem-free multiplayer experience.
Be patient, and we'll all help you out.
Think back to learning how to drive a car. It was fun yes, but didn't you just want to "hurt" that boring instructor? hehe
Anyway, we're all here to help.
the Monk