The Web Content Accessibility Guidelines want you to use Landmark Containers to confer meaning on the different sections of your web pages. However they don't require you to implement a specific structure; you should use them appropriately to make your content accessible.
In the majority of cases your page structure will contain a header, a nav, a footer and a main (possibly split into sections, asides and articles). So most of your page structures could start like this:
No matter what your chosen page structure is, it's important to maintain a consistent structure throughout your application. This helps all users understand your application but particularly helps those with cognitive disabilities.