Hi @Saima_,
As @Chris_Hofer mentioned, I do have a Mac and frequently use it to access Canvas in my full time job as a university Canvas administrator.
The first thing to check would be your MacOS version (you can click the apple logo in the upper left and choose "about this mac" and tell is what is says next to MacOS). If your MacOS version is not Ventura 13.2.1 or Venture 13.3 (or newer if someone else is reading this in the future), I'd recommend updating your operating system, which will also update Safari. If your MacOS is older and cannot be updated anymore, it honestly may be time to look in to a newer computer, as you're likely going to run into more and more odd issues and incompatibilities going forward.
If you've done the above and are still having the issue, would it be possible for you to tell us more details about the situation? Are you accessing the powerpoints from Modules, through the Files area, through links on a page, etc? Can you provide a screenshot of the error, or more exact text? There area lot of variables that could be at play here, so anything you can provide us would help us give better suggestions. If using another browser, as @SusanNiemeyer suggested, does work, let us know that too as that would further narrow down the problem to Safari.
I do want to say that I have nod had any reports from any students at my institution of this issue, so I don't think it's a widespread Canvas issue (though I could certainly be wrong).
Hopefully some of these steps help, or at least get us pointed in a direction to provide more assistance.
-Chris