on my mac when i choose system setting, click general there is no option for automatic updates

Apple is blocking me on my macbook, it asks for my apple id, i think its using a very old unused email for my Id, a Juno account that was discontinued years ago. I have been using my gmail address for quite some time. In the last few days I have been asked to use my phone for a new password for apple. I have done this several trimes, and still when i open the macbook, it asks for my apple password, i carefully enter the new password and it rejects the new password. This all seems to be connected to the icloud, i think that the old juno email my still be in the icloud as my screen name. I signed into apple via them web and it showed my old juno.com name. help.