I got a iPhone 7 as a gift but i trying to set it up and all it saying when I go to set it up it has the problem “no service “issue and I need help fixing it

Click on this link 'If you can‘t make or receive calls on your iPhone' --> https://support.apple.com/HT204027

- "Find out what to do if you see "No service" or "Searching" in the status bar. You might not be able to make or receive calls on your iPhone if you have certain settings turned on, if your software isn't up to date, or if there's a problem with your network."

'If you see No Service or Searching on your iPhone or iPad' click here --> https://support.apple.com/HT201415

With an iPhone 7 also look at this document:

iPhone 7 Repair Program for "No Service" Issues - Certain US and Asian models

https://www.apple.com/support/iphone-7-no-service/

it must be 2 reason... 1..maybe i was locked by network provider and ask the one who gave you, to contract the network provider to unclock network.. 2 it might be hardware problem maybe network IC is damaged it can’t pick network