Good afternoon jamson18,
Welcome to the Apple Support Communities!
It sounds like you are seeing an error on your iPhone 7 regarding cellular data.
The resources below will help you address this issue:
If you see an Update Failed or Apple Pay Not Available alert after iOS update or restart
"If you see this alert, there was an issue updating the cellular communication features of your iPhone or iPad. Your iPhone can't make or receive calls or text messages or access cellular data."
If you see No Service or Searching on your iPhone or iPad
iPhone 7 Repair Program for "No Service" Issues
Take care.