Here are some things to try:  

1. Click the Refresh + Power Keys.   If your Chromebook did not turn on, continue to Step 2.                                                                                        
2. Hold Power key down for at least 30 seconds or until you see the Chrome screen.  If your Chromebook did not turn on continue with the troubleshooting steps.
3. Is your batter fully charged?  If not, charge your Chromebook.
4. Do you have a light near the charging port when your charger is plugged in?  If not click the Refresh + Power Keys.
5. If none of these steps worked, please see the tech office in your building for further troubleshooting.