downloaded song from iTunes but when i open in audacity nothing shows up. just empty screen
Considering that we can’t see and don’t know what you’re doing, what does that mean?
Let’s start with which version of Audacity (look in “Audacity > About Audacity”), and then step-by -step description of what you did, what happened, and what you expected to happen.
If you are using Audacity 2.1.0, you need to add FFmpeg to import MP4/M4A/MOV/ALAC. “Nothing happening” is exactly what happens in 2.1.0 if you import a short file in one of those Apple formats without FFmpeg installed.
Or update to Audacity 2.1.2 from Audacity ® | Download for Mac OS which does not have that problem.
Gale