I figured out how to make the audio start at my selected point, rather than at the beginning of the slideshow. First, position the cursor (red line with a pointer on top) at the point where you want the audio to begin. Then, click on the audio file you want to use. DO NOT DRAG AND DROP the audio file onto the audio timeline. Instead, in the column next to the audio bin, click on the rectangular button on the bottom of the list that says "Add to Slideshow." It is a blue arrow, pointing down, with a blue horizontal line under it. After clicking that button, the audio file will be placed exactly where you have placed the cursor.