The page you select as your posts page will automatically list all your blog posts chronologically beginning with the most recent one. For the blog page it is not possible to choose page template. Different blog layout options can be selected from within the customizer.
3.1 Creating a post
Posts are entries that display in reverse order on your posts page. Posts usually have comments field beneath them and are included in your site's RSS feed.
Read more about writing a posts here: https://codex.wordpress.org/Writing_Posts