It includes

a normal Skyblock Island with custom chest

a custom End portal island

a floating nether portal with default nether 500 blocks away

A custom endstoneless End dimension So everything is floating above the Void

The Goal:

Slay the Ender dragon

Steps to achieve:

1. Get a cobblestone generator.

2. Build a place where hostile mobs can spawn.

3. Brew a weakness potion with fermented spider eyes.

4. Use the weakness potion to cure a zombie villager.

5. Trade with the villager to get emeralds and with a wondering trader to get dripstone.

6. Use the dripstone to farm lava.

7. Turn lava into obsidian and make a nether portal. (light it with fire spreading from lava)

8. Once in the nether either bridge to the default nether (it's 500 blocks away) or ride a strider there.

9. Get blaze rods from a nether fortress.

10. Get ender pearls (From Piglin trades or from natural Enderman spawns)

11. Make eyes of ender from ender pearls and blaze rods and fill in the end portal.

12. Enter and defeat the Ender Dragon.

These are all the required steps there are lots of other stuff you might want to do. Villager trading for diamond armor and tools, Building farms, Getting elytra and other late-game items ect. the possibilities are limitless