When I select the clone tool and either single or double click on the image, the clone tool shifts to a 'move image' type of function. I can't clone and there's a second image that shows up and moves around as I move the cursor.
Yes this question pops up quite regularly. Its a feature that is hidden away in a panel that should probably never have been introduced. These very basic options do not appear duplicated as they should, in the Options Bar.
The answer is - if you show your Clone Source Panel, there is a checkbox called "Show Overlay" that you need to uncheck. Experiment with "Clipped" as well.