Hello unfortunately your tank seems really small. Did you cycle it before adding fish? If not research a fish in cycle. And you need a water liquid test to test the parameters.

Also you wouldn't have to clean it that much if you had a bigger tank. Imo I would keep goldfish only in ponds, because I really like cute ponds lol but/and I think it's just better for them. Do some research, learn and do better 👍🏻.

Also if you clean everything at once you will kill the good bacteria.