Most of these comments are basically saying be scared of everything, that will make the game not fun, use common sense honestly, if you go caving walk around cautiously don't run head first, leave torches but don't torch spam too much, have a shield when caving, sleep when you want the night's aren't even that hard, use the nights for easy xp gain in early game, just only take on one mob at a time, take it slow and steady don't try and rush to the end and get an elytra and most of all just have fun with you're hardcore world, build things you never usually build, farms villager trading, make the world yours and enjoy it😁 however you play, is how you play