3. Blog
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 a page template. Styling is automatically applied as soon as you select the "posts page" in Settings->Reading.
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