you are trying to create a custom template to use with site sculptor, right?
so the guide to follow is the "Creating a custom template for Site Sculptor" tutorial on the Site Sculptor Support page" that i linked to previously:
to start using that tutorial you have to first create a template.
you can use CSS Sculptor to create a site design, then save that as a template.
once you have a template created, the "Creating a custom template for Site Sculptor" tutorial walks through adding the editable regions, then creating a menu design preset to use, then creating the site design.
once you have created the site design, you can select it as the design to use when running the site sculptor wizard.