no one ever talks, do i have to invite them to chat or is everyone just quiet
In what game? It might be different for the game you are playing but most games you can just talk by using the "white" bumper. If you want to talk to friends on your friends list while you are playing campaign or something then you can invite them to chat.
You might have to go to your dashboard - Xbox live setting and turn it on so that you can hear people.