Page Layouts and Templates
Page layouts, both for your product page and upsell page can be selected in your product setup (as shown below).
However, you cannot create them here. Instead, these are created in the store builder (as shown below).
Click Pages icon in the left menu, choose Pages, and select either Product Page (as shown above) or your Upsell Page. Then, click the pink + button to add a new layout (as shown below).
Page layouts are built using elements. Simply drag and drop elements into the page where you would like them to be. Product Elements (such as the product image slider shown below) are automatically replaced with the right information when visitors view product pages.
Once you click to Save, your new layout will appear in Product Setup.