Some theme settings won't show until you're viewing the page in the theme editor preview window to which they relate - product, collection, article and blog settings all fall into this category. Be sure to navigate to the page you want to edit, to see the options available in the left sidebar of the theme customizer!
Choose from grid or collage for your collection listing pages. It's also possible to create additional collection listing pages with your choice of collections. To create multiple collection listing pages, follow these steps. Just skip the "Create your new page template" section, as the theme already includes a "page.list-collections" template.
Enable infinite scroll to load in new products as the user reaches the end of a page and as with the collections list choose from a grid or collage layout.
Choose either wide or narrow product pages (new to version 4).
Choose image layout to be one column or two column. The latter will mean there's less scrolling for the user (new to version 4).
Choose traditional drop downs or list out your variant options. When using the listed layout, sold out single-variant products or variants which are unavailable will be shown as crossed through.
Change the cart type here to toggle whether the user is taken to the Cart page immediately after clicking the buy button on if they remain on the current page (this option is sometimes known as AJAX add to cart)