Are you saying you installed it and it works but you didn't give any user names or passwords ?
Or haven't you got that far ?
Here's a howto but I don't know if it's your version.
Basically, you use your web hosting control panel to create a database with a user name and password, then using phpmyadmin, import the .sql file you get with vpet.
Change the relevant config file to reflect your server and database.
Login to the pet control panel and set it up.
It can't create a database itself because it doesn't know your database user name and password.
You do have a database username and password for your server ?