EShop product plugin is used to display the details of a specific product in a Joomla article.
You should go to Extensions -> Plugins to filter "Eshop Product content plugin" and enable it.
Then go to edit the Joomla article and enter {eshopproduct 1} with 1 is the ID of product that you want to insert to that article. Now, if you view the article on the front-end side, you will see the details of that product there.