You can draw Mickey Mouse by using the oval/circle tool. You will have to use filled ovals and empty ovals. You will also need to use the paint bucket tool.
To capture the essence of Mickey in a drawing we need to understand Mickey which we can do by watching a few video shorts. In 'Hats Enough' Mickey explores the depths of his sole to answer the question 'If I don't have a hat, then who am I?'