New Tank Set Up

Hi. I'm new to keeping a salt water aquarium and I'm just looking for any general advice to better my understanding of marine keeping. I have a 20 gallon nano reef tank start up with live substrate sand, 2.5lbs of live rock and water from my LFS. The salinity is reading at 1.024. I had the water tested and it's near perfect with only .05 nitrate which was an easy fix. I have a nano protein skimmer, a bubble for circulation and oxygenation and a heater set to 77 degrees F. I added 15 mL of stress coat and half a gallon of fresh water to bring the salinity down. I currently have two ociallas clowns and a chocolate chip star. If there is my fish are currently hosting the bottom right rear corner. I wanted to know if this is normal. And if there is anything else that should be done to better the life of my tank.