On the set lists screen, select the set list you are interested in; the edit and play icons will appear. Press the play icon to start the set list. To help you find a set list, you can change the order and grouping in the left hand search pane.
When a song is first displayed, the song information is visible at the top of the screen. This will automatically hide after a second or two, but you can show it again by tapping any of the song text.
To change the current song in the set list, swipe left to move onto the next song, or right to move to the previous song. You can also tap on the left or right side of the screen to achieve the same effect.