This article explains how to set up restrictions and parental controls on an Apple TV.
Regardless of which generation of Apple TV you have, the parental controls (or Restrictions, as they’re now called) are available in the same place. Before you begin, make sure you have the latest software for your Apple TV. Then, to block apps or features on your Apple TV from your kids:
Go to Settings > General > Restrictions.
Select Restrictions to enable them.