Hi Mike. I am not greatly into using the program, but, this is what I did, without too much trouble.
First I selected, in the initial set up, the formats I wanted. (I selected all)
Then went to Organise - Manage libraries. Selected, for example, Music, and, in the next window, pointed to the folder where I have my music stored.
Clicking music of my choice automatically plays it shuffle or single.
Hope this helps.