The first goldfish I can remember having was Sammy. He came from a fairground in the UK, and we had him for years. Unfortunately, we kept him in a round bowl, which isn’t really a great life for a fish, but he was healthy and lived for a long time.
It’s best to keep goldfish in a tank, or even better, an outside pond, if you can have one. It’s surprising just how much water and surface area even one small goldfish requires, when you do some research about it.
One school of thought says that you need 30 square inches of surface area per goldfish, another says that you should have approximately 20 gallons of water per fish. Of course, the surface area would depend on the size and shape of the tank, but it seems that more is better. A search using “water surface area per goldfish” will bring up a variety of answers to the question.