How does one view or save a photo to the desktop when a caption has been added?

In the Photos view go to the View ➙ Metadata menu and check off all items in the menu:

Now to get the title embedded into the image file you need to export it like this:

Now you can view the title and other ITPC metadata with an app that can read those fields in a file like Preview:

Please read the following user tip and restate your question/problem in detail: Writing an Effective Apple Support Communities Question - Apple Community  

Where did you add the caption, i.e. in the Info pane or on the image itself? If on the image itself how did you add it.