The headline automatically converts to all uppers but be sure to use title case when making the headline. When you hit enter, it creates a new block. You can add a paragraph, picture, heading, etc. by clicking the + plus symbol.
I added the picture above by clicking the plus symbol, then Image, then media library. You can drag and drop new images in the media library.
When you finished writing the article, you can add a featured image if needed by clicking on “Post” in the right side toolbar and click on “Set featured image”.
After that, all you need to do is click “Publish” in the top right corner. You will have to click “Publish” twice.