Okay, I think what I need to do is add a template to my code that will create the output for me.
Should I follow the instructions here?
http://code.tutsplus.com/tutorials/advanced-use-of-attachments-in-wordpress-creating-categorised-gallery-pages–cms-21007
I am using the Sparkling theme by colorlib, it has an image.php part that says it’s for dealing with attachments. Could I just put some code in there?