My 3 yr old won a goldfish, how do we care for it, from the state fair?

sorry to disappoint but goldfish can be a lot of work, wal-mart employees don't know what they are talking about and will make things up to make money. ONEgoldfishh alone needs at least a twenty gallon tank, with a filter included, they don't however need a heater as they like cooler temperatures. goldfish are never usually picky eaters but try to get goldfish food, and only give a small pinch ONCE A DAY, giving him too much food will make him go to the bathroom more creating more bad chemicals in the water, this is why a filter is necessary as well as giving the fish oxygen to breathe, without a filter and a big enough tank, your fish will become extremely stressed, not breathing enough oxygen, being over-poisened by its own wastes and not having any room to grow to its proper size!