A store homepage is an automatically generated page on your website that can be accessed by adding /shop at the end of the domain (e.g. yoursite.com/shop) or clicking the link in your store settings:

By default, the store homepage consists of a website header, footer, and the product category “folders” that contains the category name and image. If your products are not added to any categories in the store settings, they are placed on the Store homepage category by default. Under the “folder,” products and subcategories are displayed.

Store homepage is added to your sitemap automatically and can be indexed the same way as other website pages.