Which testing server model do you have running on your machine - i.e. IIS, XAMPP, MAMP (Mac), or WampServer (WAMP5)?
What 'management end' are you using?
You will need to have set the root (super-user) password for mySql during install, - this is the password you will need to enter during the (testing-server) Sculptor install.
You will also need to create a new database within your mySql install for each new site that you develop, - so the 'database' field will be different for each site but the password will be the same each time as the database user will always be 'root' (unless you have created new mySql users/passwords for other people to share the database).
Make sure you are using the super-user (root) password, and that you are entering the name of the database you have created for your sculptor site correctly.
Post back with any queries (and say what testing server model and management client you have installed).