8 to 8.3 is fine..but best keep it at a fixed ph level as much as possible although the reading changes throughout the day..try to minimise that swing..
NO2...definitely u need it to be ZERO
NO3...as low as possible....25 may be too high for some corals...but fishes will be fine with that reading
and what must you do, keep reading more online information...not all may be correct, so just moderate all the information yourself