no not that part here is an example of the _config.php in the mysite folder.
$project = 'mysite';
$databaseConfig = array(
"type" => "MySQLDatabase",
"server" => "yourdomain.com",
"username" => "your_username_for_that_db",
"password" => "your_password_for_that_user",
"database" => "your_MySQL_DB",
// Sites running on the following servers will be
// run in development mode. See
// for a description of what dev mode does.
// This line set's the current theme. More themes can be
// downloaded from http://www.silverstripe.com/themes/
When you installed SS, you should have entered the details as above, (if that corresponds I don't the install screen to look at right now), the part you said just leave as is. Im not sure if you need the 'www.' when you enter the server address I haven't so far.
This includes some debug stuff which i find helpful.
Hope that's helpful! let me know if not!