You can access WHM (Web Host Manager) simply by typing /whm at the end of your domain:
If your domain is not yet resolved, you can access WHM here:
Your WHM username and password will be the same as your cPanel username and password (for the main account). This will be sent in an email when your order is completed. If you are unable to find this email please submit a support ticket. For security purposes, we will not provide passwords via email requests.
Note: Your billing and cPanel-WHM passwords are different.