Creating a Fantasy World Map with Political Divisions

Hello everyone! I am brand new to Unreal Engine. I am currently writing a fantasy story and have already finalized the lore and other aspects of the world. Now, I want to create a visual 3D map of the land.

I would like to divide the kingdoms into distinct political sections while maintaining one continuous map—similar to World of Warcraft maps, but in 3D rather than 2D, with names and towns visible directly on the map.

Are there any plugins I can use to generate or randomize terrain/structures so they look more natural? Any step-by-step tutorials or advice would be greatly appreciated! Note that the towns do not need to be highly detailed; I just need a broad, high-level map to look over.
Thank you!

Example: