Every page should have a link at the top, that would allow website visitors to bypass navigation, and quickly get to the main content. It is helpful for website visitors with screen readers as well as website visitors only using keyboard functionality, allowing them to get to the meat of the actual page without having to sort through your navigation.
It is especially important for sites that have a lot pages or contain a mega menu with many links. Without the ability to skip the navigation, website visitors with screen readers may get annoyed and leave without reading the content they wanted to access.
This link does not need to be visible to users who don't need to use it, so use CSS to hide the link and only display when in focus.
Below you'll find a screenshot of a page from a sample blog site. If you visit the actual site, and immediately hit "tab", you'll see this option appear at the top of the page.