Apple sending me messages regarding my storage.

Go to Settings > [name on top], and scroll to the bottom to see the devices that are using your Apple Account. The phone numbers are not relevant as a device can contribute to iCloud storage whether they include a phone number or not.

Here are some tips for managing your iCloud Storage:

Manage iCloud Storage

1113_0722 wrote: Apple sending me messages regarding my storage.

Are you sure it's Apple that sending these messages? There are many many scams involving messages and emails pretending to be from Apple. Don't trust them!

You can check your storage at System Settings>[name]>iCloud>Storage or at iCloud.com at the bottom of the page:

Don't let your storage get greater then 90%.