hi, im unable to export to mp3, i’m not to computer smart.please help! : 
To be able to export as MP3 you will need to install Lame.
Instructions are here: http://manual.audacityteam.org/o/man/faq_installation_and_plug_ins.html#maclame
at the end of all steps the pop up says unable to locate file
Get the zip of LAME and follow these steps: http://manual.audacityteam.org/o/man/faq_installation_and_plug_ins.html#maclame_zip . You can extract “libmp3lame.dylib” where you like. If you put it in the Audacity installation folder and restart Audacity then you should not have to use the Audacity “Libraries” Preferences to locate it.
Gale