Learn the basic principles of an oscilloscope, an instrument that displays a voltage waveform:
Learn how to use the NI ELVISmx Oscilloscope ("Scope" on the NI Instrument Launcher) as implemented for the NI myDAQ. With this application you can view the waveforms on the pair of analog inputs "AI0" and "AI1" as well as the left and right channels of "Audio In":