You will then be able to set a title for the blog post, add the body content, and also provide all the meta information such as extra details and media. In the blog meta you can set the image for the thumbnail.
Step by step :
1. Enter a title in the column that has been provided.
2. Fill the text editor with your content.
3. Add image here and the image will display as featured image.
4. select post format would you choose in the column that has been provided.
5. Publish it!