accessibility – Should screen readers read the content without tab or with tab?

I am designing a web application, which can be accessed by any visually impaired person. This web application contains various page and each page can have some paragraphs with links, form input fields, collapsible sections and some buttons.

Now when my user opens the page, should the screen readers read the content on my page automatically one by one from top to bottom?

Or

Should the user take control using tab key and navigate through the page and let the screen reader read the content where the cursor focus is?