Make sure the area is clean and dry, and well ventilated. Epoxy is rather nasty to breathe in an enclosed area,
The material will be in two parts. Mix well in the ration specified, and read up in advance what the working time is. Be ready to complete only the amount you can cover during that time frame. For an area as large as you suggest, about the size of a 2 car garage, I have done this a couple of times and do one half per session. That seemed to work well.