How do i make it so when i get hit by an object/person the game stops

I made a shooter game close to BO3 zombies but way worse ofcourse. But i want to make it so when I get hit by a zombie (or in this case a boy) i die and the game restarts, anyone know how to do this?

You can use the command when player collides with boy exit the game, for a better experience you could learn how to use groups.