There are two options to insert an image into your post:
Option 1: Insert an image into a post by using the "Insert Image" icon on the top of the edit section. 

• You can click the "Insert Image" icon and from the drop-down menu. Select one from the list (if the file isn't already uploaded to your Podbean account, go to "Media Manager" and upload the photo).
  
  
  
• You can also insert an image from other sites by entering the URL of the image in the "Source" section.
  
  
• You may also re-size your image by adding the height and width in the box. Afterward, click the "Save" button.

Option 2: Write HTML image tag to include the image in your episode. Check here to see how to get the image URL.

If you wish to resize and adjust the position of the image, you may check here.