I need help my cellular said Error
What is my cellular doing?
See this Apple articles below:
How to unlock your iPhone for use with a different carrier
https://support.apple.com/en-us/HT201328
If you can't activate your iPhone
https://support.apple.com/en-us/HT201407
Manually update your carrier settings on your iPhone or iPad
https://support.apple.com/en-us/HT201270
Check also the range of the mobile network, see this Apple article: If you see No Service or Searching on your iPhone or iPad