Step 1. Creating new category
You can check our Support Center on how to create new categories.

Step 2. Adding the "Categories" widget
After logging into your account, go to the "Layout"->" Widgets" page then drag and drop the "Categories" widget to either the left or the right sidebar. 

Step 3. Editing the widget
After dragging and dropping the "Categories" widget, click the icon at the right side of the widget and add the title for it. Then click the "Save " button at the bottom right of this page.

Step 4 .Viewing Site
Click the "View site" button at the upper left side of the account to see the widget you set.