If you followed step 3, you should only have to enter a few entries on the page for the site name, your UID, password, and email address. Make sure the email address is accurate. This is the only way to recover a lost password. WordPress will send you a new WordPress site to the email address, but nothing afterwards. If you need to reset the password, then you would get an automated message from the WordPress configuration to help you reset your password. You should not use the database credentials for your site credentials. Choose something different.
If you didn’t follow through with step 3, then you would need to provide the credentials for your database. You would need the Database Name (should be you.tld), database user, database password, and table prefix. As mentioned, if this is your root site, make the prefix www_. If it is a subdomain?, then use the subdomain as the prefix. Once you provide the information, you would be able to proceed as you above with setting up the site name, and credentials for the WordPress site.