hello i have my mom old phone, but this phone have activation lock
What i can do, how to remove the activation lock?
iPhone SE
You will need her Apple ID and password. Without that info you will not be able to use the phone. It would be a better idea to have your Mom go through the steps outlined in this link. Having her do this will clear the phone of her data and you will be able to easily set it up for your use.
What to do before you sell, give away, or trade in your iPhone or iPad - Apple Support