Signing in issues
Having issues signing in to icloud keeps giving network issues
iPhone 7, iOS 13
Connect to Wi-Fi on your iPhone, iPad, or iPod touch
Troubleshooting Wi-Fi issues in IOS.
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, iPad, or iPod touch
Try a forced restart.
If necessary
Hard reset.
Do a backup and try a factory reset. Then restore from your backup.
Backup - Restore your device from an iCloud or iTunes backup.