Change my occupation. I have not filed my taxes and ought to be able to update anything I want without having to create an amended return.

You enter your occupation in My Info.  The IRS does not actually use that for anything except statistical purposes. It will not affect your tax return at all.  You do NOT click on amend to change things on your as-yet unfiled return. You might need to click "add a state" so it will let you go back in and make changes (you do not really have to add a state).