[kwren]

Of course always have your car in park when doing that and when trying to start with a jumper, the ignition switch has to be turned on to "run"

Checking for a battery problem for starting your car can be as simple as turning the ignition to run, turning on the headlights to bright, trying to start and see if the headlights dim but no cranking is happening.

If this is the case, it ain't the battery.