Before to set the “Portfolio page” you have to install the “Elementare PRO Portfolio” plugin. To to this just go to your WordPress Dashboard under “Appearance-> Install Plugins”. Install and activate the plugin.
After activating the plugin, create a new page and choose the “Portfolio Main Page” template, save the page. Now this page will be the portfolio main page. If you want you can insert content into the page and will be shown above the portfolio.
To add new projects in the portfolio go to your WordPress Dashboard under “Elementare Portfolio-> Add New” and create your projects. Projects can be filtered by using categories. Subsequently, in “Appearance-> Customize-> Elementare PRO Theme Options-> Portfolio” you can set the number of project to show per page and the order.