How do I stop my Chromebook from going to sleep\shutting off frequently?

- Click the clock in the lower right corner. 

- Click on the gear icon for settings

- Click System preferences

- Click on Power

- There should be a couple settings there for 'When Inactive and plugged in/on battery' that you can change to 'Keep Display On' or 'Do Nothing'. Whichever of those two options is there.