The top level is around the 70 right now, remember that when a server have not enough teams to create a new level it repeats the top.
You start in Level 1, every season you win a level. Except for those who played the old version with the job centre where you were able to change of club so, if someone left a L50 club for a L1 then the manager level looks like 50, despite that now the club that he have will play in the L15, 20 or so...