Hello,
I am brand new to audacity and need to mix music for a dance routine. I have just downloaded Audacity and then logged into itunes from my laptop, I tried to import the songs I saved from itunes but it wont allow me to- it says it is an advance audio coding file, that I need to turn it into a wav or aiff file? I have looked on this forum and tried a few things but no joy. Can anyone help?
Please speak in basic terms, this really isn’t my forte lol 
You need to install FFmpeg.
If you are on Windows, simply download & RUN FFmpeg_5.0.0_for_Audacity_on_Windows_x86_64.exe to install it and you should be able to open AAC/M4A files in Audacity.
You can also use iTunes to convert to WAV.