And what does “Create a page and add shortcode [stc-subscribe] or use the STC Widget to display stc form subscription” mean?
1. wp-content directory is a folder on your website.
2. The email address is blank when you are not logged in on the website
3. In order to manage the subscriptions you can add a content page to your website with the shortcode [stc-subscribe]. It is also possible to add this functionality in a sidebar. You do this via the menu feature on the WordPress dashbord. You will find the STC Widget as one of the widgets you can add to sidebars.
Look at my website http://www.vandestouwe.com to see the STC widget in the sidebar. You will find the email filed empty because you are not loggen as a user.
Kind Regards, Sidney