Authenticator Setup

Just got a new PC on Monday and really struggling to 'speak Microsoft'

Somewhere I am asked to verify but struggle to provide an acceptable means.

Thought I'd try and install Microsoft Authenticator on Android Tablet and cell phone.  I use OUTLOOK desktop and have access to my Outlook accout configured together with my regular email account.  Authenticator requires confirmation but won't accept my outlook passwor,. won't send me a message to my outlook account (does suggest using my Authenticator app - which is what I am trying to set up - so not very helpful.) The email address is an old one which is no longer in use but sruggle to make changes without some sort of verification. Just going round in circles.

Guess I am missing something simple but have spent ages trying to get round this hurdle

Any help appreciated. Will try Youtube as well