To go to the ui/Theme-Builder you can go in the Admin menu >> components >> ui/Theme-Builder Pro
In this interface you can manage your pages:
- New
- Edit
- Publish
- Unpublish
- Check-in
- Delete (Trash)
- Import (only ui/Theme-Builder Pro)
Once you have created your page you can create a new menu link to this page:
use the menu item type ui/Theme-Builder >> Page: Display a page created with ui/Theme-Builder Pro.