In this train simulator from Zoo Digital, you start out at headquarters with a small amount of money based on the difficulty level. Your first objective is to connect two cities by building tracks. It's recommended that you use the city with your headquarters in it to help with research. Then you have to buy a train and set the route and cargo. You will then see your first train going back and forth and begin to make money.
To expand your rail empire, you can connect to more cities and buy more trains. Then you can carry more cargo and meet the demands of each city. You can also earn more money by creating Cargo Chains. For example, one cargo chain is Logs, Lumber, Furniture. In order to get lumber, you must set a train's route from a city that has logs to a city that supplies lumber. Then take the lumber to a city that creates furniture. These items, especially the third tier cargos, are worth a lot of money and are usually in high demand.
Buildings and infrastructures increase the efficiency of your trains. Research items also create efficiency and unlock trains that are faster and can pull more weight.