How do I change contact information and Airdrop name on a new Mac mini?

Set up new Mac mini. It has my wife's contact info for any form I fill out and also has her name on Airdrop and in Family.

The family section on my phone has my name but the mini has my wife's name. The info to fill out forms that pops up is my wife's old work email.

[Re-Titled by Moderator]