Generally everything should have arrived or be expected to arrive about a week before the contractor starts demolition. All of the boxes are to be opened and items inspected thoroughly for accuracy and potential damage and blemishes that can happen in shipping. You may have some interest and knowledge of construction lingo, but one of my roles during construction is more than a designer, I am also a translator. This is because all too often contractors become too technical when explaining why something needed to move or why they changed something they were doing behind the wall etc.
Within the first few weeks I will meet with you, your general contractor and possibly their plumber and electrician for a rough (stuff behind the walls) walk-through to assist with adjustments due to unforeseen circumstances which may affect the completion of the design intent. Before the finished tile is installed, I will meet with your contractor and their installer to physically layout the tile on the floor and with markings on the walls to avoid potential funny-looking sizes of cut tiles that would draw your attention away from the beautiful feature we had intended to focus the design around.