I am responsible for the set. Some of the things that I will do are setting up the tales and chairs and helping to set all the props in pace so that the scene is ready, finding a good fireplace GIF and set it up in the computer and the projector so that it shows the fireplace in the scene, and maybe even move the projector so that the fireplace is lower or at a appropriate place.
As for clothes, since I portray Mr.Birling, I'll wear the most fancy clothes I have, which are a dark pair of trousers and a polo shirt, possibly a shirt from my father if I can make that work. I will wear dark shoes that don't bring attention to themselves and possibly a jacket of some sort.