Choose New Post from the top or left side menu to start a new blog post. Use the WordPress editor unless you need a more complicated layout, then you can use the Elementor editor.
Add a featured image to your post in the right column where it says set Featured image. This image will display on the blog page and when the post is shared.
Optimize images in your post for the web. See how to optimize images for details.
Write SEO meta tags for your post including title and description that describe what its about. You will see the Yoast SEO section below the post edit area (in the WordPress editor). All in One SEO Settings are also below the post area in the WordPress editor.