Indeed you didn't download and install the Share Pack Code so you cannot play Online.
The Share Pack Code is now available for free, please find it on the store (directly in your console) and install it.
You should then be able to join the server.
Some additional information is available here: SHARE PACK CODE issues
I was looking on youtube when I found out u need some sort of account to access online but there is not a way to show u its stupid
i am now having the same issue as we speek, wierd part is my friend is in a party with me on xbox and hes online.... whats going on?