I am just trying to understand what you have done here.
It appears that you recently made changes to your system, such as updating your BIOS, and were then prompted to reset your PIN. This is normal behavior. Whenever significant software changes are made, especially when installing a BIOS update, you may be asked to reset your PIN for security reasons.
However, it seems that you have forgotten the password for your Microsoft account and that you have two-factor authentication (2FA) enabled.
With 2FA, you must verify your identity using two separate methods.
One method can be your alternate email address, and another can be your phone number.
If you previously set up an authenticator app, that can also be used. However, Microsoft requires two forms of verification.
Currently, it appears that you have removed all your previous security information and replaced it with a new verification method.
Do you currently have two verification methods available to prove your identity? If not, you may no longer be able to sign in to your account.
In that case, you may need to perform a full factory reset of your PC to its default settings. This will completely erase all data on your hard drive, and you will then need to set up the computer with a new account.