Someone hacked into my iPad and my iPhone
Someone hacked into my iPad and my iPhone and he’s using a passcode. What can I do?
What leads you to believe that "someone has hacked into" your devices?
If you suspect that your device Passcodes are known to anyone other than you, change your Passcodes from settings.
Settings > TouchID | FaceID & Settings > Change Passcode
If you suspect that your AppleID account or associated Password has been compromised:
If you think your Apple ID has been compromised - Apple Support