Note: This editor gives you basic styling options and will not reflect exactly how your content will appear in your store. Once you output this code to your store, your store's custom CSS will be applied if applicable.
Images: To add an image, click the button below to open your Files library in a new tab. Upload your image. Check the box next to the uploaded image and then click the "Publish All Files" button. Then, click on the file name of the image you uploaded and copy the Secure URL. In the Rich Editor, click the "Insert" tab and select "Media". Paste that address into the 'Source' box on the Insert/Edit Media popup window and click Save.
Output: To get your formatted text for use in your store, click the 'Tools' menu and select '<> Source code'. Copy all of the content from the Source code popup window and paste it into the desired text area (i.e. caption) in your store.