Under the old, legacy system you would simply enter your email address and it would send you your password.
On this system it works a bit differently.
All users who existed on ZoneEdit prior to the Big Cutover will have to confirm their account settings and set a new password upon login to the new control panel.
If you don't know your password, you can enter one of your domain names and the system will send you a temporary password to the email account in your user settings.
(If your email address doesn't work, or you do not have access to it, see this article on how to recover your password if you don't have control of your email address).
After you confirm your account or create a new account you will set three secret question / answer pairs which you will henceforth use for password recovery.