@iCloud.com email address to use

Set up the iCloud email address and then go to the Mail app to see the emails sent to that account.

Mail – Setup on a device    

Mail - If you can’t send email on your iPhone, iPad, or iPod touch

Mail - If you can't receive email on your iPhone, iPad, or iPod touch     

Log into your Apple ID using the link below and in first section under the Reachable At, see if there is an @iCloud.com email address.

Apple ID - Manage