Prevent installation of League of Legends Only
Solution 1:
What you are asking for is a feature in Windows 10 called Parental Controls.
With Parental Controls, you can set up a user account for a child and limit basically every aspect of his work : programs they can run, websites they can visit, how much time they can spend on the computer each day, and you can also get detailed reports on their activity.
For more information see :
- How to Add and Monitor a Child’s Account in Windows 10
- How to Use the Parental Controls in Windows 10