The section Portfolio in addition to the various customizations of the page, has the ability to create a dedicated page.
To create it you have to proceed in this way:
- Go to the Dashboard
- Add new page
- Add title
- Select Portfolio Standard template
- Public
- Go to the Dashboard
- Add new page
- Add title
- Select Portfolio Standard template
- Public

After updating you see the meta-box to customize the page

I’d like to customize your page
- Go to customize and select Portfolio Home Page.
- Settings Portfolio Home Page
- Select Page Name you just created
Enjoy!