You have a portfolio with two steps: 1. creating the banner thumbnails + buttons; 2. creating the project page.

Once you have both created, you need to go back to your thumbnail page to add a link to your button linking to the project page.

I'll divide the tutorial into parts: how to create the banner thumbnails; how to create a project page; how to connect your project page to the thumbnail banner; how to edit a new project page.

My suggestion is to duplicate a project page and just replace the assets with the new ones, to keep the layout structure.