A Portfolio page can be created if you proceed in WP admin menu to  Pages > Add new. You’ll get an Add Page window, where to the right you will find a menu:

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Name your portfolio page, set the number of columns you want it to have and manage other options, like sidebars, number of projects displayed on this page etc.

Please note, that by default, these settings will be like the ones you have set as default blog settings in Theme Settings, unless you change them for a specific Portfolio Page. Read More about default portfolio Page Settings -

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You can also manage what portfolio projects data you wont to be shown on your portfolio page in Theme Settings. Learn more about global portfolio page settings - open post.