Not sure what you else need.
The hostname is where your database server is. Usually localhost
$hostname_localhost = "localhost";
The database is whatever you named your database when you created it
$database_localhost = "databasename";
The username is the name of the user you created when you created your database
$username_localhost = "username";
The password is the password you assigned to the user when you created your database
$password_localhost = "password";