when there is a kingdom or any form of civilization in fantasy stories, it is usually overlooked or given a half-hearted explanation of it ex: it's magic. I know it would be a bit of research on the writer's part, but on the other hand they don't truly have to do that. the author could use something that the villages, cities, kingdoms, the capital, etc. can trade with each other. using this and what each race need to survive you could make a layout of the trade of the kingdoms, both outside and inside, throughout the year and during hard times. just by using what would be the major export that would be in a reasonable area would make for easer world-building.
cities/villages don't just pop out of nowhere, there is always a reason. the reason could be a good farming area, being a good place for sea-trade, a defensible area, a good mining area, lumbar, and since this is a fantasy world dungeons. those are the main reasons why a village that would lead to being into a city would be. another crucial point would be a place near drinkable water. just because it is a fantasy world that doesn't decrease the critical need for water.
the minor thing that a village/city can transport would be after they set up. this is usually in the form of a trade/profession a person has. this can be hunting, clothes, weapons, etc.. another thing that could be c
after you have the potential trade set up, then you have to put the trade routs down, and which one the trader would more than likely go down. a trader would go down the path that takes the shortest point while being the safest. another thing you might want to consider is the history of your kingdom. by this I mean where did the kingdom originate, why did the kingdom come to be, did the capital relocate, did they offend any other kingdom or it's equivalent. the reason why is that this would show in the story. if the capital relocated then the capital would look new and somewhere in that kingdom would be relatively good roads that people would travel one. think of it as revenants of the past.
just by taking care of the needs of the people and taking advantage of the fantasy genre, ex: making new crops, you can have a feasible kingdom.
(finally figured out what was wrong, I usually do this in dark mode. since it was in light mode I was experiencing a weird form of writer's block. now that I found where to turn this to dark mode the quality of my content will increase.)