As soon as you begin, you're given a tutorial on how to use the drawing tools in the game. While you won't be able to create any masterpieces with what's at your disposal, you will be able to put together passable, if a little crude, images for people to guess from. A free draw mode also means you can head back at any time and practice your skills with the pen.
That being said, for the most part of the game, you won't actually have to be doing any drawing at all, as most of the play is based around guessing the answers from pictures that the CPU draws for you. This is the case in the two main modes of the game, the Solo and Battle modes.