Add sidebar to category page wordpress

1. How do I add a category sidebar in WordPress?
2. How do I add a category widget?

How do I add a category sidebar in WordPress?

In the WordPress sidebar, hover over Appearance and select Widgets from the pop-out contextual menu. Drag and drop the Categories widget from the list of Available Widgets on the left side of the screen into a location on the right side of the screen, such as Default Sidebar.

How do I add a category widget?

Click on the widget (Categories) and a dropdown menu appears which lists the places where you can place this widget on your website. Select one place (Ex. Left Sidebar) from the list by clicking on it. Now, click Add Widget button located under the same list, to add it to your website.