if the tank has only been set up for a few days, you wont have nitrites OR nitrates! just ammonia. you really need to find the sticky on the cycling process and become familiar with it. your ammonia will spike, then drop as its converted to nitrItes, that will convert to nitrAtes. nitrates are the end process of the cycle and the least deadly. How many fish are in that tank? if you have too much that will cause your ammonia to spike high too. you need to get some "cycle", or seeded filter gunk from an established tank.
ammonia burn will probably kill more fish. ammonia in ANY amount is highly toxic to fish, all you can do is small waterchanges to lower it a little..
meanwhile... read up on the nitrification cycle.