My automatic car wont move. I can put it in drive or reverse, but it doesn't move.

automatic ---- probably the reverse servo/ solenoid has failed , wire problem or the TCM
run the fault codes and fix the problem unit

putting it into a gear and hearing a knock indicates that the engine mounts or transmission mounts are broken
naturally if you put it in neutral it will not move as that what neutral is
perhaps the neutral position needs adjusting as it may still be in drive
have the fault codes read to determine any sensor/servo/solenoid faults before spending big money on a transmission

Answered

Hi it sounds like a kwik fix it sounds like the oil is very low. I hope it's helps.

your transmission needs replaced.

Hi Don, have you checked the gear box oil level? Regards John

You have a failed automatic transmission. You will need to remove and replace it or have it rebuilt.

My automatic granny doesn't move that fast either. It sounds as though your reverse gear is going out, the only thing I can suggest is taking it to a transmission repair shop... sorry =(

you check the ATF (trans oil) condition this good indiccator for your trans status . (burn mean clutch inside burn ) have small chips . change ATF and filter and make sure it;s in level.