What to take as carry on for a 12 hour trip?

Hey! I'll soon be making a 12 hour flight from Canada to Germany, the flight will consist of 2 flights, and in between there will be 1 hour and 30 minutes of layover time. I am now wondering what I should bring as carry on to amuse myself during the flight. I will be traveling as an unaccompanied minor so I won't have anyone to take to... So what should I bring on my carry on?