Canvas automatically sends email notifications to students and instructors to alert them to activities within a course. There are many actions that can trigger a notification, such as changing a Due Date, an assignment submission, new grades posted, and so on. Some are important, many are helpful, while others may seem unnecessary.
You control which actions send an email notification, as well as how often an email is sent.
Canvas is generally considered intuitive and user friendly, but the fact is that any learning management system is highly sophisticated software with a wide variety of tools, settings, options, and possibilities.
There is no one-size-fits-all answer to the question, “How do I use Canvas?”