[welcome]
Yes, is it nitrate or nitrite? Nitrite would mean your tank is cycling and you should wait for it to go to 0 before adding any animals. If it is nitrate, some of the typical ways to keep that down are:
1) Good feeding habits.
3) A reasonable bioload for the size of the aquarium.
3) Enough live rock to handle the load (approx 1 lb per gallon).
4) Regular water changes.
5) Good protein skimming.
6) Nutrient export via a refugium.