Put your sand in first after a good rinse. Your water will probably still get cloudy from the dust in the sand. After the water clears up then add your rock. Make sure the rock sits on the bottom of the tank not on the sand. Check your salinity at temperature unless your are using a refractometer. Now start your cycle. Even using established live rock you may see your levels rise. Your cleanup crew won't add much to your bio load, your fish will. Are you using RO
water? Are you going for reef or FOWLR
? Best of luck on your new system!