You can login to your cPanel either via your Client Area or using the direct login you should've received from us in an e-mail called "New Account Information"
This guide will show the quick-login from your Client Area!
Start by logging into your Client Area from our website.
When you successfully logged in, click on "Services" -> "My Services"
Here you will see all of your products you have with us, some may not be active.
Press the green "Active" button for the account you wish to login to.
On your left site you will see "Actions" and there you have the quick-login link to cPanel called "Login to cPanel" simply click it and you will be logged in to your cPanel.