Here are two ways you can get information (IMEI#, etc.) from your iPhone.
The quickest way to see your IMEI number is to open the phone keypad and type in “*#06#”.
To see much more information, go into Settings>>General>>About, and you’ll see the following screen (some content has been edited).
Underlined in RED are the three important things you’ll need to have to unlock your phone using a service: The Model Name, the Carrier, and the 15-digit IMEI number.