When you jump a car battery you should let the vehicle that is doing the jump starting run for at least 3 to 4 minutes and then rev the engine for a minute or so.
Then try to start the car with the dead battery and if the battery is any good it should start.
After you get the car jump started you should allow the car to run for around 20 minutes or longer to give the alternator enough time to charge the battery.
It's best to drive the car around the block and go down the road at a higher speed for those 20 minutes to allow the alternator to produce a better charge.
An alternator will charge some at idle but it's best to drive the car to allow the alternator to work faster at charging the battery.
If your battery keeps going dead then you should replace it with a new one so that you don't get stranded.