Yes, a van battery can be used in an automobile, IF if will physically fit in the auto's battery holder tray, is the same voltage, and can be properly secured to prevent falling out of the battery tray.
Yes, there is really no van battery or car battery. There is just an automotive battery. Installing a battery with more Cold Cranking Amps (CCA) is fine and will just provide more power in cold temperatures.
put the bigest battery that will fit
Jump the car from another car battery or hook a charger to the battery.
You can get a new battery, you can jump start the car with jumper cables and another car with a charged battery. You can also put a battery charger on your battery to give it a charge.
If the battery has more cranking amps than the recommended battery and will fit into the battery carrier box the answer is yes.
Is there power to the starter "S" terminal? What car?
Disconnect negative cable first from old battery and connect it last when installing new battery.
yes
No
Yes
No, it will do nothing
many things can do it suck as junk battery, junk alternator , or leaving anything on in the car