2002 Saturn SL2

I have a 2002 saturn sl2 it sat for a few years but we got it started took it to a mechanic got the fuel filter changed and put a brand new battery in other that that the mechanic said it looked good it's been running fine for weeks we don't drive it everyday but at least a few times a week. We drove yesterday and obviously parked it overnight. It was pretty cold out last night not below zero but still freezing. This morning it wouldn't start. The lights and everything turned on the battery is only a few months old but when we turned the key to start it nothing happened. It didn't even click.