I'd second Hoops' recommendation. You can cycle a tank without fish in it. Certainly boring to look at, but a lot easier on the fish. Also, Damsels are, IMHO
, fish from hell! They are very aggressive.
Generally speaking, it will take six to eight weeks for a marine tank to get through the nitrogen cycle. It will take at least six months before it will be completely cycled. After the nitrogen cycle is over, the water continues to "evolve." Once the NH4
levels are down, then consider adding fish. Of course at that time you need to consider a plan for adding fish. Not all fish get along with each other. Likewise, put the wrong fish together and you might have an aquatic disaster on your hands.