Nitrate, nitrite, & ph. What should they be? Right now.
Nitrate 20 ppm
Nitrite 3.0
Ph 6.8
Your tank is not cycled properly.
Basically when you first set up your tank and put your fish in it they create waste, that waste breaks down into ammonia which can be deadly for fish. Luckily bacteria will develop (this takes a bit of time though) to "eat" the ammonia and "poop out" nitrite, which can also be toxic to your fish; but then more little bacteria develop and "eat" the nitrite and "poop out" nitrate, which we then take out with water changes.
As your tank cycles your ammonia will get very high, then as it is eaten by the beneficial bacteria it will drop to zero (0), as it drops you will notice the nitrite start to go up; the nitrite will also get very high, then drop back to zero. As it drops back to zero you will see the nitrate go up; when your ammonia and nitrite are both at zero and you have seen the nitrate raise to at least 30-40ppm the tank is considered "cycled".
You may lose some fish during the cycling process, so expect that... A good dechlorinator such as Seachem Prime will help detoxify the ammonia during the cycle and should definitely be considered.
Sorry if it sounds like I'm speaking to you or explaining this to you like you're a child, I'm tired and figure its enough to take to google.
Do you know your ammonia level? This will help you to know how far through the cycle you are.
Also, a stable pH is better for most fish than trying to use chemicals to lower/raise it. Also something to research.
Your Nitrite is fine honestly theres not much you can do about that people can keep fish in all kinds of it. However for pH and this depends on where you live and what fish you have but for me 8.0 is best check your states pH water levels. You can find items on amazon to help raise it.
I'm not trying to be mean here (as I said I'm tired) but you could also do to read up on what I've mentioned.
And welcome to mfk.
Disclaimer: I do not know everything, nor do I claim to. Always do your own research and always cross reference.