Building a map in Minecraft (builder, minecraft)

Congratulations!
You need to build a map of 12k by 12k blocks in the theme of MMORPG.
Currently, it's all in the ground, but there is a bit of relief (custom map). You need to improve the map by making everything not so smooth, and creating completely new biomes with different blocks (in other words, you need to improve the relief). New biomes should be made in a science fiction theme.

In addition to the relief, you need to build 3 large cities (approximate size of each is 1k by 1k). Some of them will have walls and empty spaces for renting territory (and just parks, markets...). Each city will have its own style of buildings, and they should be different. Approximately 15 residential buildings, 5 options for a blacksmith, 5 for an alchemist, 5 for shops, 5 for everything combined, and for the guild of players, adventurers, a bank, etc. (the exact number of buildings, their sizes, and everything else will be discussed in private, as this is just a draft for now).
You also need to build adjacent settlements of small sizes; fields near the city (and even in it) and beyond; roads; trees (each biome with its own, and preferably 30 styles of each tree); dungeons; caves; mines; rivers; volcanoes and anything else you deem necessary and beautiful.

You can build the map in your imagination, the main thing is that it fits the theme and is logically constructed.