A short summary on how to add and update your skills and interests lists in the platform.
Navigate to the Platform website and locate your profile picture (or your name, if the menu is expanded), situated on the left side menu bar.
You will see a page with a form with the profile data entered upon signing up. 
Scroll down to locate the sections labeled "Skills" and "Interests". Choose the tags that are relevant to you (keeping it to a maximum of 5 is recommended) and then click on the "Update Details" button found at the bottom of the page.