My iPhone is disabled on iCloud

Have you forgotten your Apple ID?, Check your Apple ID via your email box, see this Apple article: If you forgot your Apple ID

If you forgot your Apple ID email address or phone number - Apple Support                  

OR see -> Having trouble signing in?

https://iforgot.apple.com/password/verify/appleid

If you've forgotten your Apple ID email address or phone number

If you've forgotten your Apple ID email address or phone number – Apple Support (UK)

See -> If you can't connect or sign in to iCloud

If you can't connect or sign in to iCloud - Apple Support

See the following Apple articles:

If your Apple ID is locked or disabled

If your Apple ID is locked or disabled - Apple Support (CA)

If your payment method is declined in the App Store or iTunes Store

If your payment method is declined in the App Store or iTunes Store - Apple Support

If you see a message that says “Your account has been disabled in the App Store and iTunes”

If a message says "Your account has been disabled in the App Store and iTunes" – Apple Support (UK)