All faculty and TAs will have a link to Commons on the left side navigation bar in Canvas, just above the Help link. After clicking through authorization prompts the first time you access Commons, you will arrive on the main landing page. Once there, you can do a keyword search for all institutions that participate in Commons (which is the default setting), or you limit your search solely to Dominican by using that as a keyword.
After finding and clicking upon an item of interest, there will be an IMPORT INTO COURSE button that, in turn, will enable a menu listing all of your courses in Canvas. Be aware that if you import an Assignment it will import into a newly-created Assignment group called "Imported Assignments." You can move the imported assignment to its proper group and delete the Imported Assignments group after doing so.
For many resources, you will also have the ability to download the item as a Common Cartridge file, when can then be imported into your Canvas course site. Note that videos recorded using the Panopto/Course Video menu must have their default permissions adjusted in order to be shared on Commons, as will embedded Panopto videos on a Canvas page. Panopto video creators should submit an IT Support Center case if you wish to share a Panopto video with another user or otherwise make it public.
Additional information with screen captures can be found on the attached PDF document. Also, you should refer to Canvas' extensive online help regarding Commons.