Apple id and icloud problem

What happens when you try? Error message(s)? More information would help. If the Settings are greyed out, have you checked Settings/Screen Time for any restrictions?

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         

Try a forced restart.

Reset Device.     

If necessary

Hard reset.        

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.      

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