Follow the steps bellow to edit a specific section Elementor page builder-

• Click on Pages
• Hover over the Page name to see the options
• Click on the Edit with Elementor link to edit the page with Elementor page builder.  Then the page will appear with the live frontend preview and editor.
• Click on a widget to edit it. The widget editor will appear at the left side of the screen.

See the process in an animated GIF.

via GIPHY