Blog posts, also known as articles, are composed in the Shopify admin and their appearance is controlled by the theme.
Access theme settings for blog posts
Every time you publish a new post to your store's blog, Shopify will generate a new page and URL for it. To access the settings for these pages, navigate to a post in the theme editor and then click Article pages under the Sections tab.
Display breadcrumbs on article pages
Select Show breadcrumbs to include secondary navigation with the current location of a visitor on your website, as well as how they got there. Note that there are multiple places where breadcrumbs can appear on your site, but checking this setting will affect only your blog article pages.
Enable social sharing
This option displays social sharing icons to the bottom of each of your posts. These allow readers to share posts on Facebook, Twitter, and Pinterest.