Here are a few troubleshooting tips for the school Chromebooks sent home.
If the device says locked
Make sure it is connected to your WIFI. Settings had to be changed to allow use off school grounds. They will get the new settings after a connection.
If it is still locked, the school will need the serial number to verify the settings.
Depending on what building the Chromebook came from, there will be a different login flow. Younger students use clever badges. If you have an older student trying to sign into a Chromebook setup for clever badges, they must click sign in with a different account, not next.