Before you can create products to sell in your store you need to setup categories. Categories are just labels for the types of products you sell, like Apparel, Jackets, Hats, Accessories, etc…
To get started, go to the store app and click on the Categories tab.
To create a new category click on the “Create” button above the table and on the right, this will open the new category dialog.
Enter the desired label for the category and click “Save” when done. Repeat this for each category that you have.