Creating shapes is pivotal to playing Dungeons & Dragons. Whether to indicate a wizard's Fireball or a dragonborn's breath weapon, shapes can come in all, well, shapes, and sizes!
To start drawing shapes, select the Shape tool from the toolbar. The shapes menu will appear above the bottom bar. From here, you can click the colorpicker button to change the color of the shape you are about to draw.
Got the location of your shape wrong? You can move the entire Area of Effect shape by switching to the Select tool and clicking-and-dragging on its surface area.