Add an audio file to your composition.
Add a black solid to your composition (above the audio layer). Set it's blending mode to Add.
Effect menu > Generate > Audio Spectrum (or Audio Waveform)
Set the audio Layer to the audio layer in your comp.
Tweak to taste.
I saw your locked duplicate post in the Lounge. There you said you had no idea how to make the image you have of a soundwave "move." Since that thread is locked, could you provide some more information like how you want your animation to look or if you're asking if After Effects is the software you should use? There are a lot of ways to animate a soundwave. Maybe share the image you have that you want to animate, and let us know what sort of result you are hoping to achieve.