Welcome bro! Glad to have another enthusiast in this hobby. I hate to spoil the fun but starting a saltwater tank is not as easy as 1-2-3. The saltwater you bought, usually they call it here blue bag is one of the worst saltmix that is available right now. (Please refer to what happen to Bro Bok on this thread
viewtopic.php?f=7&t=16728&hilit=bok) So if you are really serious in pursuing this hobby I would advice you to change saltmix as early as now.
BTW, meron ka na din ba hydrometer to measure the salinity of your water? also test kit to measure the ammonia, nitrite and nitrate level while cycling your tank. These are the essential things that you need to have first.
RE Live Rock, the term live rock itself doesn't mean na buhay yung rock na binenta sayo. Actually they are all dead rock since they came from skeletons of dead corals and other calcerous matter under the sea. They call it live rock because of microscopic and macroscopic organism that inhabit inside and outside that rock.