Unfortunately, tags and categories can’t be imported/exported to the CSV. I am really sorry!
We completely understand the importance of this feature and do have plans to look into this in one of the future updates. Please upvote this request to get notified about any changes - Bulk import for tags and categories.
For the image import, the images will show up in the widget if you add their URLs to your CSV file. To get an image URL, you’ll need to host the images on a service (for example, Google Drive, Imgur or any other platform) that allows public access to these images 