How to use the Portfolio
First of all you have to install Jetpack plugin.
You can do this by going to your Admin Panel > Appearance > Install Plugins, there you can install all the recommended plugins for the theme.
After you installed and activated Jetpack plugin, go to Jetpack > Settings
And on Writing enable the Portfolio option:
After that you will see a new section on your Admin Panel:
You can start adding items there and the when you select a Portfolio template you will see all your items on that page.
To create a Portfolio page, just create a new page and use the Portfolio Half as Page Template