This is a web based course, right? I don’t have to install anything locally to run the cells. When I try to run the very first cell it does not run the cell and shows an error “tag”. Clicking on it gives no description whatsoever as to what the error is about.
Typically this sort of “not trusted” error comes from your computer’s internet security tools. Perhaps it doesn’t like (and is trying to block) your computer’s connection to the course assets.
Firewalls, VPNs, and anti-virus tools can cause this.
See if you can adjust any of those items.