Terraria – How to move to a new world and keep the stuff

You can go exploring some corrupted/crimson areas (randomly picked at world generation) to destroy the shadow orbs/crimson heart waiting for you at the bottom of chasms.

Each shadow orb/crimson heart destroyed will provide you some loot, and make a meteorite land on the world. Once the meteorite has fallen, go find the site, and mine the meteorite ore. This will allow you to craft some meteorite gear and weapons.

Once you've destroyed three shadow orbs/crimson heart, it will make the Eater of Worlds/Brain of Cthulhu spawn, allowing you to fight two different bosses.

Note: The shadow orbs are protected behind some ebonstone/crimstone, which you will not be able to mine with your current pickaxe. Just buy some dynamite from the Demolitionist and use it to access the shadow orb. Or you can buy purification powder from the Dryad, which turns the ebonstone/crimstone into the easily destroyable standard stone.

It sounds like this is what happened:

1. You had your world file. We'll call it World A.
2. You copied your world file and gave it to your friend. We'll call that World A Copy.
3. You and your friend dug through the Jungle, then discovered and defeated a Queen Bee in World A Copy.
4. You went back to your own World A. The minimap shows what you did in World A Copy but the world itself does not match the minimap.

The information about whether you defeated a Queen Bee (or other bosses) is recorded in the world file, so you will need to defeat a Queen Bee again in World A.

Or you could have your friend give you the World A Copy file and replace your old World A file with it.

The reason the minimap does not match the world is because the minimap is stored with the player files, not the world files. Each world file has an internal ID number that connects it with a player's minimap files. Because you copied a world, both World A and World A Copy have the same ID number, so Terraria uses the same minimap for both worlds.