Create sidebar – show sidebar, NOT widgets

Hello,
when I go to Appearance – Sidebars and I create some sidebar, add fill it with some pages, maybe some Categories, how can I display it in the left sidebar? All I can do, is go to Appearance – Widgets / Widget Area and fill the Sidebar with Widgets, but not with the content from the Sidebar in the beginning.
I’m using Avada theme, but the settings for Sidebars are set to OFF, so it should not affect this.

Or can’t I do that? Can I only show widgets in the Sidebars, and not content, which I define in Appearance – Sidebars? Why is there the section Appearance – Sidebars?

The page I need help with: [log in to see the link]