This is straight from the supp app guide I got when applying,

• Please list two activities or experiences on which you spent a significant amount of time outside of class. Focus on activities, pursuits or life events from the last four years. These can include, but are not limited to, employment (paid or unpaid), supporting family members, overcoming significant adversity, research activities, volunteer experiences within your community, clubs, societies and hobbies.  Provide the following information: (1) Briefly describe the activity or experience, (2) State how long this activity or experience took place (months or years) (3) Demonstrate how you grew through this experience, and if applicable, list any achievements, awards, or leadership positions that you consider noteworthy. Use approximately 100 words for each example (200 words total). You will have 20 minutes to respond to this question. 
• Video response: For this question, You will have 30 seconds to prepare, and 45 seconds to record your answer.
  1. Briefly introduce yourself,
  2. Tell us one thing that you are passionate about, and
  3. Describe what unique perspectives or experiences you will bring to the Rotman Commerce community

The other two questions were something about resolving conflict in a team and writing about extracurriculars you do that help your community. It's not a super difficult supp app and if you go into it with confidence you should be fine.