You can display any page (i.e., About Us, Knowledge Article) to the portal users even before the login.
For that, you need to select the options “Before Login” and the “At Top” in Page Nesting at the time of creating the Page Builder of any entity/page.
If you have enabled any page by selecting the Form that needs to appear without Login (Before Login page), it will appear before Login page. So the users who are not registered yet can also connect with the organization by sharing details as per the Form.