If you're finding resources aren't opening, it could be that your school system blocks access to Google Drive. To confirm if this is the case, try connecting to ochre.org.au and opening resources while you're on a different internet connection.
Although not ideal, you could try these workarounds:
Download resources at home, which can be used offline in the classroom.
Purchase an Ochre Premium Annual Subscription which includes a full unit download feature. This allows you to bulk download all resources within a unit to a zip file on your desktop.