You need an Apple ID to download items from the iTunes Store, use Genius, or subscribe to iCloud Music Library. It consists of an email address (for example, emilyparker@icloud.com) and a password.
Note: In some locations, you can use a phone number instead of an email address as your Apple ID. For more information, see the Apple Support article Use your phone number as your Apple ID in China.
If you’ve purchased items from the Apple website or bought a photo book, or if you have an iCloud account, then you have an Apple ID. If you don’t have one, you can set one up using iTunes.
For more information about Apple ID, see the Apple ID Support page. To create one, go to the Apple ID website.