Hi @derchegy.
What you've chown in your screenshot is the global navigation menu in Canvas. You'd find discussions in a course menu, whihc would appear to the right of the global menu. With that being said though, each individual course in Canvas may have different features/tools enabled or disabled. There are many classes, especially in-person ones, where there may be no online discussions at all. Along those same lines, online discussions could also happen in a 3rd party tool. I would recommend reaching out to your teacher(s) through whatever means they have given you to ask about this for your specific class(es).
I hope this helps!
-Chris
