Enliven takes advantage of the Jetpack portfolio content type. This is the portfolio archive. You need to install and activate the Jetpack plugin first in order to get this. Then go to Jetpack > Settings from your WordPress dashboard and enable the Custom content type module. After you did it you will see a new menu item called "Portfolio" in your WordPress dashboard. Just start adding your portfolio items from there. After you’ve added some projects, they’ll be visible on your website at http://yourwebsite.com/portfolio/. And this text can be easily changed from Customizer > Portfolio Setting