Follow next steps to setup a portfolio page.
Step 1 – Go to admin Dashboard -> Pages -> Add New
Step 2 – Set page name & select from Page Attributes -> Template ->Portfolio * Column[s]
Step 3 – go to Dashboard -> Portfolio -> Add New & add all portfolio details.
Voila, you have created your first portfolio article you can check it on previously created Portfolio page.
Step 4 – Go to Dashboard -> Appearance -> Customize -> Portfolio & configure portfolio page features per own needs.