You navigate the content of this web site using the site content menu and the navigation bar.
At the top of each page you find the navigation bar.
From the navigation bar you can show/hide the site content menu and show the table of contents for the current page. The navigation bar also includes breadcrumbs, i.e., a sequence of links showing the navigation path to the current page.
Depending on your screen size or web browser window size you might see or not see the site content menu to the left.
If the menu is not shown you will see the icon in the top navigation bar. Press this icon to show/hide the site content menu.
In the navigation bar you find the table of contents icon . Hover your mouse over this icon to show a table of contents for the current page. In the table of contents you find links to the various headings on the current page.
You find links to the start page both in the navigation bar, above the site content menu and at the top of the site content menu.