There is a tag on the case, facing the rear, it looks like this...
and 2 big bolts around 1" 3/16 or about, the lower is the drain, the upper is the level check and refill... loosen the top one first to make sure that you can refill.... as that stage you can check the fluid level that should be about to be flush with the fill hole the vehicle being on a level surface...
if it is one of the NP TC, dextron ATF, probably dextron III is the current version... I forgot how many quarts... may be 3, but buy 4...