

Each game has their own little quirks and focuses. From what I remember sc3000 is best to start in a corner. You only get half the pollution from buildings on the edge, which is pretty big in the early game. You also get easier access to trade partners which is a good source of income later. Public transportation is also important, and very expensive, so you need to aggressively maintain a strong budget surplus to keep expanding.
There’s also some magic numbers to know as you get more familiar with the game. Airports, farms, ports, and subways all have sizes you need to keep in mind when planning.
Monopolies are not the only thing that governments are supposed to prevent. Anti competitive practices are supposed to be illegal regardless of monopoly status. The same is true of cartel behavior.