You should add sidebar contents using registered widget areas. There are 4 sidebars that will be displayed according to page types.

Main Sidebar

This contains widgets to show in sidebar of post archive or homepage .

Shop Sidebar

This contains widgets to show in sidebar of shop page.

Shop Top Sidebar

This contains widgets to show in sidebar of shop page when sidebar position is set as Top in Molla > Theme Options > WooCommerce > Product Catalog.

Product Sidebar

This contains widget to show in single product page. You can set single product page layout in Molla > Theme Options > WooCommerce > Single Product.