Car not starting after replacing the alternator

My alternator was going bad so I decided to replace it with a new one and get new spark plugs too. It's my first time doing an alternator and I forgot to undo the battery terminals before I started. I torqued the spark plugs to spec (13 ft/lbs) and put the new alternator the same exact way the old one came out. When I tried to start the car I got nothing. No dash lights no crank no power. I went to AutoZone and O'reilly's to test my battery, alternator, and starter to make sure all parts are still good and they are. I'm not sure why my car isn't starting, the only thing I can think of at this point is a bad wire in the wiring harness to the alternator.