Multiple options for user, some not available

1. How do I enable another user option?
2. How do you fix another user on this device uses this Microsoft account so you can't add it here?

How do I enable another user option?

Open the Settings app, then select Accounts. Select Family & other users. Scroll down to the Other Users section, then choose Add someone else to this PC. If the new user already has a Microsoft account, enter the associated email address, then click Next.

How do you fix another user on this device uses this Microsoft account so you can't add it here?

Go to Profile & system, and then select Add or switch > Add new. Enter the email address for your Microsoft account, and then press the Menu button  to proceed. Or select Use another device to sign in by using your mobile device.