Hit a plus sign in one of the boxes below. See what happens on the left. See if you can get an idea about what content-style and advanced refer to. Feel free to experiment on this page.
Also play with those icons below. They have to do with adding content like boundaries, blocks and preform templates. When you are ready to view what you’ve done, hit the eyeball icon near the top right. Or just publish by hitting publish. Then to make edits again, hit “edit with elementor”.