The DayZ Xbox One First Person Mode is a feature within the game that allows players to engage in a different perspective. As a standard within the game players will view the experience from the third person. At any time, server allowing you'll be able to give a hold tap to the right stick in order to switch the viewing. You perform the same hold tap in order to go back into the third perspective.
Either will give you an advantage depending on the situation. There's also a special mode called "Hardcore" known as server HC when searching to play the entire thing in the first perspective as it locks third person out. This allows for a different way to compete against others, in case you want something new to try. For now, read about the bow and arrow inclusion for the Xbox One platform or view the DayZ Hub for other details about the general game of zombies.
Read About DayZ Xbox Hardcore Mode Details
View our DayZ Hub