WooCommerce is a plugin for WordPress. This means you already need to have your own self-hosted WordPress site. You cannot use a service such as WordPress.com that hosts the site for you.

Many of the recipes in this book require only WooCommerce itself. Some of them ask you to download a plugin from WordPress.org. Anything on WordPress.org will be completely free. Some recipes will require premium WooCommerce extensions. The vast majority of these are available on WooThemes.com. These extensions may be necessary for something such as, billing someone on a monthly basis, but they are not necessary for the core functionality. You can build a store without any extensions. If you don't wish to purchase any, you can skip the recipes that require these.

If you are a developer and you wish to use a test site, that will be fine. There are only a couple of recipes in this book that need an actual live site, and this requirement is clearly flagged in the introduction to the recipe.