There are a variety of options for getting help with teaching technology tools.

The help button on the global navigation bar will connect you to 24/7 Canvas support so if you have an issue outside of normal business hours this is your best bet. You can search their guides, call the support line, or chat online with a representative.
The Teaching and Scholarly Learning Team can assist you during normal business hours. You can email teaching@rice.edu.
The Canvas Status Page will show you if there are any known issues at that moment.