Check out the tab at the top of the screen labeled "Anthropomorphic",
it's the basis for the next project.
Then, for homework, do a google search for old trees, in your sketchbook, full page, design a tree that has a human quality about it. No background and no texture on the tree. If you are stuck for an idea look at the example I have drawn on the "Anthropomorphic" tab.
We will look at your animatics.