Is my phone unlock

Hi you can go to Settings-General-About scroll down Until you see carrier lock. If your phone is unlocked it will say No Sim Restrictions. more Information is here on how to unlock your iPhone. How to unlock your iPhone for use with a different carrier - Apple Support. Please note Apple can't unlock your iPhone for use with a different carrier. Only your carrier can unlock your iPhone.

If your iPhone is running iOS 14 or later, you can check it in Settings>General>About>Carrier Lock (it should show "No SIM Restrictions").

If you don't see that message, contact your carrier, after reading this support article:--> How to unlock your iPhone for use with a different carrier - Apple Support

Regards

Giulio