well i personally build a reef from the base up, as in from letting the tiny's like pods and micro wporms establish first, then a clean up crew like hermits, snails maybe a few shrimps etc and then a few soft corals and then i start adding fish. But thats just the way I do it, having fish in there is no problem you can add corals and things fine.
but that yellow tang is an algae eater (good thing) he is not your worry with regards coral nipping, its the Koran angel. Its of paramount importance (that means its like vry important, did i say how important it it?) to research your fish first. After a while you get to know them well, what they eat, where they swim, how they swim, whom likes whom and whome will kill another, which get big and ourgriow a tank, which are messy feeders, who will eat your corals and who wsill sna ck on your shrimp. Between all that yoiu still find some awesum fish, you just have to know which will suit your tank.
@belinda do you have some links CT can study on appropriate fish he might look at?
that koran will not im afraid, and now that you have ONE yellow tang in there he will have a territory and thus adding other yellows isnt a good idea, indeed you will have to see which other tangs you could add.
but i am running ahead a little, lets rather help you build up your base of clean up crew and some soft corals to start with, its the easist way to go
