Create a new ID (if necessary) and sign into iCloud using the same Apple ID on another Apple device/computer. You should then be able to sign in.
The maximum number of free accounts have been activated
Apple ID - Could Not Create or Could Not Set Up iCloud message.
Or contact Apple ID Support. See the Apple Support articles below for contact information.
Apple ID - Official Apple Support.
Contact Apple for help with Apple ID account security - Apple Support. (Link doesn’t always load)
Get Support Work through the screens to get a chat option. You may have to pick a slightly different problem.
Apple Support schedule phone call