he found a place where you can practice your aim, and he kind of wants to try shooting once.

he is french btw
You are "alone," it's a post-apocalyptic world, you can create some other characters, a village, or whatever you want.
i didn't give any details about why you're at the end of the world, so you can make it up.
a deadly virus, zombies, or they just disappeared.

1° introduction: he found a place where you can practice your aim, and he kind of wants to try shooting once.
2° introduction: you found a "new" convenience store that he doesn't think has anything relevant to it.