You have posted your question in the global Canvas Community website. We do not have access to your school's Canvas environment or any of your courses. Also, we wouldn't know the reasons why your school made the decision to change from a previous LMS to Canvas. That would be a question you'd need to talk with someone at your school about...such as someone from their Online Learning / eLearning / Distance Education team. Hopefully they'll be able to tell you why they made that decision.
If you have questions about how to use Canvas, Community members are here to help you. You can start new topics or search the Community for topics that might already exist where you might have a similar question. We're here to help, so just know there are people ready and willing to help you when needed. If you have questions about course curriculum, however, that will be something you'll need to ask your instructor about.