You can find your IMEI 1 or 2 ways:
By opening your phone dialer and "calling": *#06#, your IMEI will be displayed on your screen.
or by opening your settings on your device and selecting "About Device".
IMEI numbers either come in a 17 digit or 15 digit sequences of numbers. The IMEI format currently utilized is AA-BBBBBB-CCCCCC-D: AA: These two digits are for the Reporting Body Identifier, indicating the GSMA approved group that allocated the TAC (Type Allocation Code).
Your IMEI may start with a 35, 09 or 86.