Canvas is the exclusive LMS (Learning Management System) for the UH main campus.
Students can view their instructor's comments on the Grades page. Most comments are located in the assignment sidebar. If your instructor marked up an assignment directly in an assignment submission using inline comments or annotations, you can use the View Feedback button in the assignment's submission details page.
Canvas article: How do I view assignment comments from my instructor?
Canvas article: How do I view annotation feedback comments from my instructor directly in my assignment submission?
Canvas Student App
Canvas article Android: How do I view assignment comments from my instructor in the Student app on my Android device?
Canvas article iOS: How do I view assignment comments from my instructor in the Student app on my iOS device?
Students can also set notifications (email and/or push) for submission comments.
Canvas article: How do I set my Canvas notification preferences as a student?
If you are not seeing your professor's announcements, this is most often due to your individual Canvas notification preferences, which each student controls. You may want to check the following:
How students can check their Canvas notification settings:
In Canvas, click Account → Notifications
Find Announcement and confirm it is not set to Notifications Off (they may choose Immediate, Daily, or Weekly) at both the account level and for this course.
Also, check Account → Settings to confirm the email address they use is correct, and then check their email spam/junk folders.
Also note that Daily notifications are delivered around 6:00 PM, and Weekly notifications are delivered on Saturday between 3:00 PM and 5:00 PM.
Student reference: How do I manage my Canvas notification settings?