Issue starting car in a 2007 Toyota Camry

I have a 6 cylinder 2007 Toyota Camry XLE. Recently, my alternator went bad which almost completely drained by battery. I got my battery charged up and replaced the alternator. Two days after replacing the alternator, my car wont start. There was no electrical output and when I tried to start my car, not even the starter worked. I had my battery tested and battery was putting out 12.7 Volts. Since the alternator was just replaced, I replaced the starter. After replacing the starter and reconnecting the battery, all the headlights and dash lights immediately came on but I still can not start the car. Any solutions?

The only electrical thing I messed with was taking out the electrical input from the battery to the starter and then reconnecting it. I made sure to reconnect the positive and then negative terminals of the battery.