No, seriously, why do they? It's not like the construction workers don't get paid their wages if they aren't given such projects, and, unless you are buying the resources from overseas, the only cost for the construction materials for the state is wages/salaries of the workers who are involved in the relevant processes.
Am I being swindled?
Until you have a construction company in your country you are using foreign resources and labor and must pay for them.
Gameplay wise, there is a button that looks like a crane at the bottom right and one that looks like money, when constructing a building. The crane is for planing construction so your construction companies start constructing them.
Inside the construction company you must select where they get the resources like steel and concrete, usually you want some nearby warehouses, if you make the resources yourself make sure to fill the warehouse with them, otherwise buy them from abroad.
People, if they live close to the construction site will go to work there, if its far away you need to buy a bus in the construction site to move the people.
Bear in mind the game tells you how much working days it is needed to build any building and how many resources you need, its only if you are buying the building when money matters and the game gives you an amount based on how much the labour and resources cost.
Once you make your own construction industry, leveling and manipulating terrain is free too!
It does cost a little fuel. It's always super annoying when you start flattening a hill and then all the bulldozers drive away to get gas.
I only wish its range were global, I hate needing to create so many construction sites all around the map.
Which implies that there are no other cities in your country.
Another person has explained to me that that is, apparently, the case or something similar to that is.
All of the land that you see/can build on is your country. If there are no other cities, then there are no other cities. If you haven't build a construction industry, then there isn't one.
If I'm not mistaken, the game is essentially about starting your own soviet republic under the USSR (and presumably handwaving away the idea of non-monetary cooperation between soviets) so yep, no pre-existing anything.
I think the premise is you're a tiny as fuck micro-nation in the Eastern Bloc that was literally just a few villages before WWII, so yeah you're improving a lot from the rest of the USSR.