I set up my ten gallon tank let it run for a week then put in two goldfish a month later my nitrates are high I do 25% change and vacumn once a week. Water looks and smells clean added prime and put in safe water how long before my tank cycles and nitrates go down?

Nitrate is the end product of the aquarium cycle. The only effective way to make it go down is water changes. Most likely your issue is that the tank is much too small. Goldfish are messy fish and they get big. 10g isn't nearly large enough.