1. Create a world

Create a simple world on your Minecraft with the Copper Extension mod added. Simple step, to needs to get further.

2. Find the datapack folder

Go into the datapack folder of your brand new world. First you need to find the world folder. To find it try to go on this path.

Once you find the world folder. Normally, there is a datapack folder included. If not you can create it. This is where your gonna make your datapack.

3. Create the datapack

Finally, once you are in the datapack folder, you can create your datapack. But to create a datapack, it need to follow a specific structure using folders and files.

But if you are a bit lazy, and your Minecraft world is still runnin’, you can execute this command /datapack create <id> <description>. Then here is the datapack structure generated by the command:

pack.mcmeta: This is the main file of your data pack. It contains the basic informations of the datapack. This is what is should look like:

{
    "pack": {
        "description": "This is the description of your data pack",
		"min_format": 88,
        "max_format": 88
    }
}

The min_format and max_format is the Minecraft version range which your datapack is “useable”. On this exemple, version 88 correspond to Minecraft version 1.21.9-1.21.10. You can get a list of the datapack versions here.

Finally, on the data folder you can add the Namespaces and get started making your datapack! I don’t want to do into details but basicly a Namespace is a group to categorize where the data should go. If you don’t know about Namespaces, I really recommand checkout this Minecraft wiki page.

If you want more details on how to make your own datapack. Checkout the Minecraft Wiki.

4. Add custom data

Once you created your datapack, you can finally create somethings. If you want to learn how to add custom oxidation, waxing or lightning effects, then check the sections.

Also by the way, if you needs help to make a datapack, there is a great website which I still use these days.