dude straight up you need the test kits before setting up the tank but just your saltwater master kit, then your sump, then more LR, then a ro-di unit if you dont have one already( depending if you feel like hauling water from the store) then lights. cause if everything is not straight as far as your water and your biological filtration goes more lighting is gonna cause problematic algae. corals need a stable environment so furthermore you need your system rock solid and stable. and the biggest thing is left for last, TIME yes time takes care of a lot, it takes a bit for everything to get into its "grove" so it handle itself. imo the main goal would be to build the strongest bio environment you can while you save up for the equipment you need