Transfer from old phone to new phone
Transfer from old phone to a new phone. What if the “new phone” is actually my friend old phone?
Question marked as
First - and VERY important - have your friend completely “scrub” himself out of the device by following these steps:
What to do before you sell, give away, or trade in your iPhone or iPad - Apple Support
When properly scrubbed; when 1st powered-up, the phone should prompt for a language and then display “Hello”.
If it doesn’t do this, DON’T accept the phone.
ONLY THEN, transfer your stuff to the newly scrubbed phone:
Transfer data from your previous iOS or iPadOS device to your new iPhone or iPad - Apple Support