You can use any size paper that you have available.
If you do not have a permanent marker, any black marker will do or simply skip the step of using the marker.
If you do not have watercolor paints available to you that is fine. Please use another medium to add color. You can use crayon, colored pencil, pastels, or any other coloring supply that you have. Marker will work too but please use one of the other items instead if possible.