If you are new to cPanel then you can check : How to login to cPanel, Navigating around in cPanel, How to login to cPanel.
After successful logging into cPanel,the first thing you should do is update contact information. To navigate to this tab, click on your user icon:
From the drop-down list select Contact Information 
Its important to keep your contact information up to date since the server uses this information to send critical email messages.
Once you have entered the email address, click on save.
