Canvas has a variety of ways for you to communicate with your peers and instructors.

Announcements: can be used to communicate a message to everyone in the course.
Conversations (also known as the Inbox): like emails, Conversations can be used to reach individual instructors.
Discussions: great for interactive discussions between two or more people within your course.
Calendar: provides a daily, weekly, and monthly view of all items that include a scheduled date, including graded assignments and events.

You will normally get an email or push notifications for several of these functions. It is important to note that in Canvas, notification settings are determined by user preference and not by course. However, UCC policy advises that all notification preferences be left at default, should you choose to turn notifications off you may miss an important announcement or message.

This 4-minute video from Instructure outlines some the conversations tool in Canvas.