Google is your friend, do a search there.
"I should buff the floor once week with wax? Is that correct? Plus is it necessary to buy a floor polisher or buffer as early as now,"
You should buff or burnish the floor according to how often your contract states it should be done and how much traffic the floor gets.
Hard to say if you should buy one as early as now when we have no idea what you are talking about, give us some detail please.