How can I see all my groups on one page?

You can see which active groups you are currently a member of:

Under Groups in the global left navigation bar. Here you will find all the groups in Canvas WU that you are currently a member of - including already archived groups (previous groups), and cross-course groups.
Under Courses and All Courses you will see an overview of the groups you are currently a member of.
In Calendar you can also filter calendar events by your groups here.

NOTE: Ask your group leader or the teachers to choose a meaningful group name including the course name, if this has not already been done. It will be easier for them to assign groups, especially if you are a member of several groups in one semester.