Creating your portfolio page and adding portfolio items is very simple with this theme because it includes a built-in Portfolio custom post type so as long as you know how to create posts and pages you can also setup a portfolio!
Create Your Portfolio Page
First, create a new page by going to Pages > Add New.
Give your page a name, and then select the Portfolio template in the page attributes box.
Publish your page.
Adding Portfolio Items
Go to Portfolio > Add New to create a new blog post.
Give your portfolio item a title, add content, select a category, and set a featured image.
Publish your portfolio item when you’re done. Your most portfolio posts will be displayed on your homepage via the homepage template by default.
To create a portfolio item with a gallery simply add images to the Image Gallery metabox. If you add images here, the portfolio item will automatically be formatted to a gallery post.
Navigate to Appearance > Customize > General Theme Settings. From here you can edit Portfolio archive page layout options, and edit the archive entry displays.