As your aquarium is in the process of cycling, your fish will be under much stress. Ammonia and nitrites are toxic to fish (and other fauna), so you would be best conducting 50% water changes on a daily basis to keep their levels low.
If you have anyone nearby, see if you can grab some squeezings from their filter media so that you can jump start your cycle as well.
In the meantime, I suggest you read up on the nitrogen cycle, and to prepare for the possibility of losing a few fish.
Just tested and there's no ammonia and nitrates are 20ppm (safe) but the nitrites are 3.0ppm should I still do water change or leave it?