2000 Chevy Impala car wont start

I was looking over the car for blown fuses or visable breakes in wireing due to the message screen started flashing "low fuel", "battery", "security", and kept rotating these three messages. The fuel gague and the cruse control are not working. I was also trying to check these out also. While doing this I saw that the main harnes plug was not fully connected and I pushed the connecting lever and it came loose. Ipushed it back together and snapped the connector and now the car wont start. I am looking for an answer to why the messages keep comming on and what the connection between the harness comming apart and the car not starting.