Migration from macBook to Air leaves duplicate user account
I had a macBook Pro with a battery that failed and couldn't be replaced. It had a single user account John. I bought a new MacBook Air, ran setup and had a single user account "John Smith". I ran migration, it took forever but looks like everything was correctly copied onto the new computer. I am no left with 2 user accounts - John which has all my data and John Smith which appears to be an empty user account. I went to delete the user account John Smith but it prompted me to turn off "find my mac" on my appleid. that made me nervous so I quit.
Can I safely delete the account that was created when I installed my new computer? if so, how can I connect my appleid to the new account if I do delete it?
MacBook Air 13″, macOS 11.2