ApocalypseX
So does he have a family or not? My suggestion is for the writer to quit trying to play both scenarios. #1 a random person teleported into a new world will not care about the family of the person he replaced. #2 as a foster kid/orphan, caring about others is the literally last thing you try to think about as your survival comes first. Have him worried about food and a place to sleep
Bad start for the story...guns will just attract more zombies and get the mc killed...unless you have unlimited bullets don't use guns in a zombie apocalypse....also guns are boring...how about magic or telekinesis...also huge burden to pun on a guy to make him the saviour of mankind...let the mc be free to do what he wants...don't give us the ending of the novel already...