Some cities have more than one stations. For example, London and Paris have five or six each. Stations and tickets are clearly marked. There would be no problem if you check well.
Take home a broader perspective.
Explore the city you are in. Try to stay at least more than one day at a place. To explore a place, the best option is to walk or cycle. Rental bikes are everywhere. Cycling or walking through the off-beat tracks can give you an enriching experience.
When it comes to food, go for the local special is a safe bet. Check where the locals go. Is there a queue to get in? Modest bistros can offer the best food. What more? They are economical too!
Smart travel can give you the best tour experience and is money well spent.