Trains, train stations, and public transportation

I have to take a train from the Munich airport into the city, and then another from Munich to Prague, Prague to Berlin, and then from Berlin to Amsterdam. When I arrive in Munich, I will have had little sleep after a 15 hour plane trip. I don't have very much experience with trains and public transportation. Yes, I am afraid.

1. How will I buy a ticket?


2. How do I know where the train will arrive? and which train to get on?


3. Will I know when to get off the train?


4. What if I get on the wrong train?

If I know the questions, I can find the answers. Most mistakes have some remedy. I'm not afraid to ask for help. But I worry. I'll try not to. My son will be along to share my pain. Worry doesn't come naturally to him. He doesn't...maybe because I have it covered for the whole family. Maybe I can learn something from him.