You can set the static home page through the wordpress customizer.
If you already have the page with the portfolio, just follow the steps below. Otherwise, create the page with the portfolio page template.
On the left menu, select Appearence, then Customize. Scroll down and you will see the option Static home page. Click on this option and select the Static page radio button, then a option will show. Click on the dropdown menu and select the page that you want to be the homepage. No need to edit the code.
This also can be done by Settings > Reading.