there is a dipstick at the back of the engine , but is that the engine oil d/stick? it has a red top
there is only one dipstick! with a red top ., so where is the oil dipstick? confused!!!!!

it is probably the one , follow it down with a torch, it should go to gearbox.
you should have engine running and in Park to check the oil, you fill it down the dipstick,