New iPad for child with own Apple ID

We are getting my son a new iPad for Christmas. He has an existing iPad that he has had for about 4 years and it is under my Apple ID. This seems like it shouldn’t be hard, but can I create and ID for him in Family Sharing, but restore what he already had on there? Do you set up as new iPad with new Apple ID then go to iCloud to restore from the main family share account? Seems like it would be straightforward, but I have been burned before with these things. Thanks in advance!