Hi Bryant. I'm Greg, 10 years awarded Windows MVP, specializing in Installation, Performance, Troubleshooting and Activation, here to help you.
It will set up the PIN for the account you are signed into at the moment. It has no ability to create another account when setting up a PIN.
If ti's a Local Account and you don't have a password then first set up a password in Settings > Accounts > Sign in Options. Log out and log back in to make sure it works.
Then go back to the same place to Add a PIN, test that it works, too.
If you are operating a Microsoft Account then you already have a password, just add the PIN in Settings > Accounts > Sign In Options.
Based on the results you post back I may have other suggestions if necessary.