>>2127539
The game is quite simple. Your "resources" are materials and people. To develop an area, you need to:

>1. have building materials available nearby
>2. have people arriving at a nearby station

Passengers are "generated" in a denser area, where they board trains. They will be unloaded at the next station, regardless of what is there (it's not realistic at all). So the idea is to unload passengers at the station where you want to develop the area, while making building materials available at that location. Then just wait for the buildings to start appearing.
Manufacturing, transporting, and storing construction materials will almost always be a loss. But you lose money in this part to make 10x more with the subsidiaries you will build/buy in developed areas.

The only thing you need to be careful about is taxes. There is a tax on profits that you pay every month, but you have two other taxes that will be calculated on the last day of the year and must be (automatic) paid on April 1 and May 1, and these taxes are absurd. When you get to the end of December, it's best not to do anything else and just save money to pay the April and May taxes, and only then start spending money again.