di yiy love the classic caves only challenge of minecraft? i do and wanted that for 1.18 so i took the time to get the world set up. this is a 1.16.5 world that has been reopened in 1.18. there are no 1.18 features besides the lighting. no mobs will spawn unless absolute 0...so work fast. there are all of the trees scattered in a 1k radius around your spawn point. there is even melon pumpkin and sugar cane. everything is close enough for you to find and spread across the world yourself. keep inventory is on and creative mode is enabled in case you want to adjust some things.

/gamemode survival
/gamemode spectator
/gamemode creative

/gamerule keepinventory on
/gamerule keepinventory off

fire tick is on
mob grief is off using data packs
villagers will farm