Welcome to AA! One of the necessities is a good reading assignment. Check out one of my favorite starter books, The Conscientious Marine Aquarist by Robert Fenner. Outdated with repsect to cycling with fish, but still a good initial eye opener to the hobby. It'll help ya decide on fish only or reef. Some reading will tell you that live rock is a certainty, not something to possibly move onto like you say above. After you decide on inhabitants, it'll help decide on some of the equipment.
The second neccessity is gonna be patience.
Go slow and read for now.
Cruise thru our SW
articles section for valuable tips also.