Xbox360 help! I need help with xbox live!?

ok i need major help from an xbox expert!!! plz......

i have connected to xbox live (gold membership) i can add friends.

But i am unable to join chats and i cant play multiplayer online wat is going on?

i rang xbox and they told me to change port numbers but i dont no how to do that......plz help....i realy want 2 start playin....tell me if u need more onfo .......my router is ZyXELXbox360 help! I need help with xbox live!?
I am not for sure but try this. If you are on a minors account and your parents have a password on it then this might be why. When you create your account when your under 18, then the parental settings automatically sets it so you can only talk with friends only. This might be why you cant play with people. So get your parents to change your settings for every option (or what they want) and put it to everyone and it should hopefully work.Xbox360 help! I need help with xbox live!?
check your connection speed

reset your router setting

and update xbox360 sowftware