This is torture

How big a tank did you put the goldfish in? For the first fancy goldfish, it should have at least 30 gallons of water and 10 gallons for each additional one. I think that what happened is that since it was a new tank (probably less than 10 gallons, it died of ammonia poisoning. In an established tank, there will be bacteria that will break down ammonia to nitrite and another that will break down this nitrite to nitrate. This takes a while for the bacteria to build up to enough to break down this ammonia and nitrite to less dangerous nitrate. If you put the fish in a bowl then it probably died of oxygen starvation because the only way that it was getting oxygen was at the top of the tank (bowl) and if the water is filled to the top there is less air water surface for the oxygen carbon dioxide to be exchanged.If you want to get a fancy goldfish then start out with a large enough tank and put in chemicals to get rid of chlorine and chloramines as well as heavy metals, make sure to not overfeed the tank and do regular partial water changes with water that has been treated for chlorine, chloramines and heavy metals as well as being the same temp. If you can only have room for a 10 gallon tank then a Betta (Siamese fighting fish ) would work well in that size of a tank and there are a few other fish that can be put in with a Betta for company. You will need a heater and filter for the Betta. Hope that this helps.