hold ⌘ = draw rect · ⌥ = draw ellipse (overrides the tool) click select (again = group) · drag move / resize · ⇧click add · drag empty = area select · ⌘Z undo · ⌘D duplicate · ⌫ delete · dblclick text = edit
Pick Rect / Ellipse / Line / Path / Text above and drag on the canvas.
Or hold ⌘ and drag = rect, ⌥ = ellipse.
Or load a Sample from the list at top right ↑