Minecraft wiki entry for Superflat_survival, associated text: After you get 5 emeralds, it's time to trade with wandering traders. Because there are no generated structures, the only way to get wood is from saplings sold by wandering traders. Regardless of sapling-type, it always costs 5 emeralds per sapling, so use your emeralds to buy preferably an oak sapling (produces apples, which are required for a later step), and a bucket of fish if you have leftover emeralds, any other trades are useless. If the trader did not have a sapling to trade, you can kill the trader to get 2 leads and his two llamas, though be careful, as attacking the trader causes the llamas to spit at you.