Honestly, you don't want zero No3 and Po4.....as has been said you will starve the corals. I made that mistake and I learned from it. I now try and keep my No3 at around 5 and Po4 at around 0.03 (which will often read 0 on the Hanna Phosphate checker due to the limits and accuracy of the tester, Phosphorus tester has a better lower limit and resolution)
As for corals try the plating Montipora, a great intro into SPS and they are cheap and easy, also the Pocillopora I found to be very tolerant to mistakes. Birdsnests are pretty easy too.