If you are not on mobile, then your browser has the answer to almost everything, without logging out. The url where you are playing always contains the server set (language) and world number as in:
us1 . elvenar . com / game
us2 . elvenar . com / game
us3 . elvenar . com / game
etc. to #8 (note some smaller language groups may not have all 8 worlds available.
Those 8 world names are:
Arendyll
Winyandor
Felyndral
Khelonaar
Elcysandir
Sinya Arda
Ceravyn
Harandar
If you forget them, go to the front page of the forum here and there is a sub-forum for each world, listed in order of the numbers above (as those are the order in which the worlds came online)
So if you are on us7.elvenar.com, you are on U.S. English servers in world Ceravyn. If you are on en3.elvenar.com you are on the international English servers on world Felyndral.