(This guide is possible in easy mode and medium if you do gamer mode is way harder.) . So when you spawn do the tutorial , craft wooden tools. than iron tools if you want even higher tools. than make some pieces of armor like a helmet and boots. Than you need to get some powers like the frog , knuts hammer , sniper scope , life steal , regenaration (you dont need to have all of these) . Than find a challenge Big chung statue or wait for him to spawn. Kill Big chunk and figth him with a pickaxe and not a sword . (if you have double jump is easier)When he does an attack jump to try to avoid it.
If you want a how to beat Gronk guide do this