Sorry for the nube question but Ive just upgraded to Sierra and seriously need my armory up and running, won't launch.
Armory definitely works for me on 10.12.2. Just sent and received coins today, actually.

That said, can you do me a favor? Go to /Applications/Armory.app/Contents/MacOS/py/usr/lib/armory/armoryengine/ and edit ArmoryUtils.py at Line 1267. Once saved, start Armory and see if it finishes starting up.
Old:
LOGINFO(' Preferred Encoding : ' + locale.getpreferredencoding())
New:
prefEnc = locale.getpreferredencoding()
if prefEnc == None:
if os.environ.get('LC_ALL', '').upper() == 'UTF-8':
prefEnc = 'utf-8'
else:
prefEnc = 'Unknown'
LOGINFO(' Preferred Encoding : ' + prefEnc)
EDIT: Added a suggested fix.