If you are unable to change settings on your CloudReady device, you might not be the owner of the machine. The settings of CloudReady devices can only be changed by the owner of the device (ie. the user who logged in to the device first).
In the event you were the first user to log in, and you are still not able to change any settings on your CloudReady machine, you can try logging out of your device, rebooting it, and then logging in again. In most cases, users are able to change settings on the second log in.
You might be unable to change the settings on your CloudReady machine because it is managed in the Google Admin console. When devices are managed, usually the Google Admin account is the only one able to push any changes in settings to the devices. Contact your Google Admin Console admin to request changes for your device.