I’m auditioning for voiceover work and they require 96kbps instead of 128. How do change this in Audacity? 
I presume that you mean “how to set the MP3 format” ?
See here for how to do that: http://manual.audacityteam.org/o/man/file_export_dialog.html
Do they also specify “mono”?
Audacity automatically exports in stereo or mono depending on the content of your Audacity project. If the project contains any stereo tracks the the export will be stereo. For exporting in mono, ensure that all tracks are mono before you export (convert stereo tracks to mono if necessary http://manual.audacityteam.org/o/man/tracks_menu.html#stereo_mono)
Avoid converting from one MP3 format to another if that is at all possible. Converting the original recording to MP3 or from a high quality WAV file to MP3 will give better sound quality than converting from MP3 to MP3. Encoding as MP3 always loses some sound quality, so if you convert from one MP3 file (which has already lost some sound quality) to another MP3 file (which loses more sound quality) then the result may be disappointing.
Thanks Steve, that was the last piece to the puzzle…for now. 