"The usual settings" means 6 inches width and height, Resolution:72 pixels, and mode: RGB color, with contents white.
Here are my drawings for the first lesson. Unfortunately, I cannot draw well with the mouse. The first drawing is of "Betty":
For the second drawing, I have the "flowers", using "bucket" and discovering that EVERY line must touch!
I was not satisfied with this drawing, but hopefully it will be okay for the lesson. Drawing with the mouse is definitely not my forte. The scene has three birds in it, anyway.
Not a good underwater scene, but I think I got the idea of how to use the eraser, airbrush, and the dropper for getting the same color.