[JustOneMore20]

I wouldn't worry about putting chemicals in. Some of them don't work and if/when they do they could affect your readings (give you false readings).

I would do water changes daily until the ammonia and nitrItes are 0.

I'm a bit afraid to ask, but what size tank is the goldie in? And what type of filter do you have on the tank? Goldfish are messy fish and can quickly foul the water if you don't do water changes regularly. The smaller the tank, the more water changes you need to do weekly until you can get him a proper size tank. 1 Goldfish will eventually need 20 gallons to himself.