Some web hosts allow you to change the theme of the cPanel web hosting control panel. cPanel comes with several preconfigured styles, and your web hosting company has the option of creating their own or modifying an existing theme with their branding.
cPanel can send notifications to users concerning exceeding disk, bandwidth or email quotas. These notifications are sent by the hosting control panel, and are separate from any settings you may have in your host's billing system.
You can turn on and off notifications, and set which email address receives notifications in cPanel.
cPanel has a Getting Started Wizard who steps you through the cPanel features. It is quite comprehensive and walks you through almost everything, including advanced features you may or may not be interested in using or need. When you first log into cPanel, a pop up dialog will appear asking you if you want to go through the Getting Started Wizard.