If your car has the 5-gear automatic gearbox, then it should have a long narrow tube at the back of the engine bay on the left side (when looking from the front standing opposite the car), capped with a black cap (usually also fixed with a small red plastic tab that needs to broken). You'll need to buy a dipstic on eBay, then measure the ATF level while the car is on level ground and the ATF at working temperature.
Normally you'll need STAR or iCarsoft in order to check the ATF temperature, but in this case you are only trying to see if there's a significant amount of ATF missing, so an inaccurate measurement will do - i.e. just make sure you drive the car before checking and the transmission is fully warmed-up.
BTW, on the 5g box, a known weak point is the pilot bush (the thick electric connector), that tends to develop a leak over time, though this should have caused slow gradual loss of ATF (which you would have noticed when the gear shift became sluggish) rather than a sudden drain.