You only have one password to log in to cPanel (your control panel) itself. You can change this password at any time from the “Change Password” icon within cPanel.
While each addon domain can be given a separate FTP password, they will all share the same cPanel as your primary domain and the same cPanel user name and password.
More details about addon domains:
Custom FTP accounts may be created to allow user access to specific folders on your account.
Instructions on setting up a custom FTP account may be found here:
Each email account has a separate webmail login, allowing an account to be checked without having to provide access to all accounts.
Here are some instructions on how to log into Webmail: