Omg whats wrong with my goldfish?!?!?

ok so i just got 3 new gold fish and i put them in a tank about the size of someones head and they have a fake plant and some rock. i just got them today and i washed the bowl and the rock then filled the bowl about half way or a bit more they i put the fish (still in the baggy they put them in at the pet store) in the powl the the water temp would not freak them out. i know you should have the water cleaning stuff but the lady said you dont need that if you have soft water and i do. so it had been about 15 mins so i let the fish out of the baggy them i put the fake plant in with my hand and let them be for a hour or so. after that i gave them some gold fish food(not lots just a pinch or to.) they were fine at first but now they are just sitting at the bottom of the tank. did i do something wrong?! what should i do?