We all want that magic world creation preset that just lets you select multiple biomes and create whatever world you want, but unfortunately, the only way to create custom worlds is through data packs.

I tried creating my own data pack, following these tutorials:
https://www.youtube.com/watch?v=SsehGR1yir4
https://www.youtube.com/watch?v=7x4orazkO_s

However, when I tried to drag and drop the data pack to a new world, Minecraft failed to validate the data pack, see if you can find any errors in my file structure or text.

my file structure: .minecraft\Unfinished datapacks\dunes of doom(contains my pack.mcmeta)\data\dunes\dimension\dunes_of_doom.json

dunes_of_doom.json:

{
  "type": "minecraft:overworld",
   "generator": {
    "biome_source": {
      "biomes": [
        {
          "parameters": {
            "erosion": 0.0,
            "depth": 0.0,
            "weirdness": 0.0,
            "offset": 0.0,
            "temperature": 0.0,
            "humidity": 0.0,
            "continentalness": 0.0
          },
          "biome": "minecraft:desert"
        },
          "parameters": {
            "erosion": 0.0,
            "depth": 0.0,
            "weirdness": 0.0,
            "offset": 0.75,
            "temperature": 0.0,
            "humidity": 0.0,
            "continentalness": 0.0
          },
          "biome": "minecraft:badlands"
        }
      ],
    "type": "minecraft:multi_noise"
  },
  "seed": 1568552693,
  "settings": "minecraft:overworld",
  "type": "minecraft:noise"
  }
}

my pack.mcmeta

{
  "pack": {
    "pack_format": 15,
  "description": "i have no idea..."
  }
}

Of course, now that I'm typing it, I noticed a bracket missing from the biome list. Thanks in advance!