Parameters Quarantine salt water

[Barry95]

I recently noticed ich after adding a new fish to my tank, it’s been a week and half and I have finally set up a 20 gallon QT tank all in one with a air stone. Tonight I moved each fish into the new tank set up, there are 2 clown fish, 1 wrasse, 1 watchman goby, and one flame hawk. I picked up some medication by the name of Fritz copper safe but haven’t dosed anything yet and I ordered a API copper test and ammonia badge is there anything else I need or any tips on how to dose this tank safely with out causing harm to my fish