I'm homeless and someone gave me a iPhone but it I can't get it unlocked

You must have the cooperation of the original owner or the iPhone will remain useless forever.

The iPhone was probably previously stolen.

How to remove Activation Lock - Apple Support

If the phone's original owner parted with the phone voluntarily, they should have followed the steps in this Support article before giving it to you.

What to do before you sell, give away, or trade in your iPhone or iPad - Apple Support

If you can contact them, and they are wiling to help you, they could prepare the phone properly and hand it back to you.

If you cannot contact them, or they are not willing to help, then the phone you have now is effectively the same as a lost or stolen iPhone. We cannot remove the Activation Lock for you, and Apple will not.