The current tutorial world has a simple setup to help with this.
Load up the tutorial world, go forward and turn left where the two trading villagers are. In the chest are some paper and emeralds. Take them, and then trade with the villager on the right (wearing white). He will trade you an emerald for your paper. He will also trade you items for emeralds.
Even though the description states that you need to mine them or purchase them, trading the emeralds AWAY to the villager also works. It's easier than they say it is. So when you have the emeralds, trade them back to him, and it will count for the achievement.
If you don't get it, quit out and restart the tutorial world as needed.