Simply put, Edge One-Pager is a simple page which categorizes a page into different sections.
First, you should create a page, check this link. after that, by adding a section, you can complete the page that you are creating step by step. After creating each section (our suggestion is full height section for a better appearance) go to page option settings and enable the options Edge One-pager. For more information on page option you can head over here.