Click on "Logout" in the top right corner, the on that is blacked out is the one you are playing on.
Once you move your cursor over it it will say "Is current player."
There are different severs as well. You can see which server you are in by looking at the URL. For instance the url for this forum has beta in it which means that this is the beta forums, any TW url will say which server it it... eg EN etc...
