When you install Zenphoto successfully you are sent an email that gives you :-
The location of your Zenphoto website
The URL to manage your Zenphoto website
The username and password to manage the site. (usually admin and 6 characters for the password)
Sometimes the email is not received by a users nominated account for whatever reason, but a copy is available for inspection under support history.
Search by subject for an email starting:-
Subject: Success installing zenphoto to ...
I believe that reset password information is also emailed and possibly available in the support history. I have not used this feature yet.
Opinions are my own views, not DreamHosts'.
I am NOT a DreamHost employee OK! :@
Act on my advice at your own risk!