ICloud

You are sign in here .  .  .  with your Apple ID & Password (?).

Your Apple ID is the personal account you use with all Apple products and services. It includes the email address and password you use to sign in, as well as the contact, payment, and security details that you use with Apple.

You can’t merge multiple Apple ID accounts.

Check ⤵️

If you can't connect or sign in to iCloud

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

Contact Apple for help with Apple ID account security

Contact Apple for help with Apple ID account security - Apple Support

Some things you can try. Do you have access to another WiFi network where you can try? That has worked for several people.

Try a restart.

Restart your iPhone   *

Restart your iPad.   *

Try a forced restart. See the section towards the end of the article.

Reset Device. -

If necessary

Hard reset.     -

Do a backup and try a factory reset. Then restore from the backup.

Restore to Factory setting.      *

Restore - If you see an error when you update or restore your iPhone, iPad, or iPod.   *

Backup - Restore your device from an iCloud or iTunes backup.     *