How would one randomly generate a map using GKNoiseMap

I'm building a game (survival of course...) that needs a randomly generated map that generates anew every time the user presses my new game button the small amount of research I've done so far led me to believe A. it is very hard B. there aren't any tutorials on the subject

what I'm asking is if you could point me to a tutorial or documentation explaining random map generation

(like mini dayZ, Minecraft, or ark survival evolved type maps with a tile based 2D generation like mini dayZ mostly)