Any discussion should have very clear directions and expectations. For example, do you expect hem to write two paragraphs or answer more than one prompt. Do you want personal examples or are they to share resources or images they have found to support a statement. Is it graded or not?
In a hybrid course these directions may be in the course calendar/syllabus. But it is also advisable to include them here in the description of the actual discussion. The same is true of assignments. It is important to do this because as students move through the course module using the "next" buttons, they can see all the needed directions without having to go back and find it in the syllabus.
There are some options for discussion. One minute into this video explains those options.
Here is some more detailed information on using Discussions.
Using due dates on graded course assignments helps students see the course work in the Canvas calendar.
You might also consider sharing a video with the students about using the discussion forums in Canvas like the one below.
218 - Discussions from Canvas LMS on Vimeo.