All of these sections are known as widgets and are accessible via Appearance > Widgets.
It will look like this:
This appears on a blog category screen.
This appears on a single individual article.
This appears at the top next to the logo so long as Header Style 1 is selected. See more
This appears if you've chosen a homepage template which includes a sidebar.
This appears on a page so long as 'Full width' is not selected via the Template dropdown.
This appears if you have installed WooCommerce
This is the main footer section.
This is used usually to just display copyright information.