Now you have added a Microsoft account you may need to enter the password to the account you have used to login to your device going forward.
To change this go to sign in options on the accounts page to customise your user experience such as adding a pass code for quicker login or use other security options such as Windows Hello, fingerprint recognition or a security key to name a few.
If your computer has multiple user accounts, it’s recommended at this point to make sure that any other user’s accounts are still able to login to their accounts normally.