the water will clear over time, and when you add your sand, its just going to get cloudy again. Giving the tank the required time is all you can do at this point. Once you start your cycle, you do not need to do water changes until the cycle is done. Ammonia = 0, nitrite = 0 and nitrate is generally going to be high. a water change will bring this down a bit, and then you can consider a few fish. Untill this point, adding fish can really cause your tank to spill some water lol. Patience in the hobby is a major requirement.
Good luck, keep us up to date with the progress and of course any other questions you may have down the road.