You have two possibilities. The first is to tap on the “…” on the right of the track (or album) you want to queue (and you got several queuing options there). Another one is to change the behaviour of a tap on a track. By default, tapping on a track will play it, interrupting what’s currently playing. If you go to the Remote preference (bottom right), you can choose between three different behaviours. The second will add the track you tap on to the queue (next item to be played), the third behaviour will add the tracks you tap on to the queue (last on the queue).