if your referring to your characters from the gPotato days, then you won't find them until your old gPotato ID has been bound to your my.com account.
to do that please open a support ticket:
http://support.my.com/games/kbPage/54/ and provide the information about your old account.
The support will then merge the 2 accounts for you, giving you access to your old characters.
p.s it will help if you set a username on your account here first.
-Wraith