The Genesis eNews Extended plugin is designed to be used with a newsletter service such as Mailchimp, Aweber, ConvertKit, or any of the other popular newsletter services. You can Google “Genesis eNews Extended + whatever service you choose” and there are bound to be some tutorials and videos to guide you in getting that set up. Here’s the plugin info page where you can read about installation and get support: https://wordpress.org/plugins/genesis-enews-extended/
To configure a Genesis eNews Extended widget you can drag and drop the widget from the Available Widgets area to one of the theme widget areas.
Here are some tutorials for getting the most popular newsletter subscription services integrated with Genesis eNews Extended: