All customers on a Cloud VPS hosting package can access their WHM (Web Host Manager) interface by opening:
where yourdomain.com is your actual domain name.
If your domain is not yet pointed to your VPS, you will be able to access the VPS via its server name (e.g. if you are hosted on vm7777.sgvps.net, you will be able to access your WHM via http://vm7777.sgvps.net/whm).
When you access WHM, you will receive a warning about the SSL certificate used. The reason for the warning is that by default cPanel uses a shared self-signed SSL certificate. You can safely accept the certificate - the connection will still be secure.
Next you will be asked for your WHM login credentials. The WHM username is your cPanel username and the WHM password is your cPanel password. Once the correct login details are provided, you will log in to your WHM and will be able to manage your Cloud VPS.
For more information on how to access, manage and use WHM