returns an error when logging in

It sounds like you are having a problem signing in with your Apple ID. Maybe one or more of these document will help you.

Recover Apple ID:

If you forgot your Apple ID password  

https://support.apple.com/en-us/HT201487

If you forgot the passcode for your iPhone, iPad, or iPod touch, or your device is disabled

https://support.apple.com/en-us/HT204306

If you forgot the answers to your security questions

https://support.apple.com/en-us/HT201485 

https://support.apple.com/en-gb/HT204169

If your Apple ID is locked or disabled

https://support.apple.com/en-us/HT204106

If your device has been disabled in the App Store and iTunes

https://support.apple.com/en-us/HT208856

You can also contact Apple ID Support for help

https://support.apple.com/apple-id

 For additional support, in the case of iTunes, you can Contact iTunes Support using this form https://support.apple.com/en-euro/itunes-contact. 

You also can contact iTunes World-Wide support by via text or chat using this link (follow the links in the read)

https://support.apple.com/choose-country-region/itunes

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

Try a restart.

Restart your iPhone, iPad, or iPod touch https://support.apple.com/en-us/HT201559

Try a forced restart.

Reset Device. https://support.apple.com/en-us/HT201412

If necessary

Hard reset. https://www.wikihow.com/Hard-Reset-an-iPhone

If there are restrictions in Screen Time that are preventing access, you will need to restore the device to factory settings. Do not restore from a backup made when the Screen Time code was active.

If there aren't any Screen Time restrictions, do a backup and try a factory reset. Then restore from your backup.

Restore to Factory setting. https://support.apple.com/en-us/HT201252

Backup - Restore your device from an iCloud or iTunes backup. https://support.apple.com/en-us/HT204184