Is there a way for us to test a Conference on a dry run basis with no students present?

You can set up a Canvas Conference in your Familiarisation Area to test how to use Conferences as an instructor. However, you will not be able to access the conference as a student using the ‘student view’ functionality. More information on the Canvas Conference interface is available here. You can also set up a test conference in MS Teams and perhaps invite a colleague to become more familiar with the process and how it works.