There is no "supposed to be" level for pH, it will be what it will be. Trying to change pH is not a good idea as pH, GH and KH are in a relationship. For example, if KH is high, adding chemicals will change pH initially then it will bounce back to what it was. Yoyoing pH is bad for fish.
GH, or hardness, is more important to fish than pH, and it is always a good idea to keep fish which need the same GH as your tap water. You should be able to find your hardness on your water company's website. You need a number and the unit of measurement rather than vague words - the unit is important as there several they might use.