I think I used "punch" incorrectly.

Question

1) What do you call the machine into which you insert your train ticket and you get the date and time stamped on it (??).
Before you go on the train, you have to ..... your ticket.

Answer 1

You can use "stamped your ticket."

And Ms.Sue explained this to me: In European train [and subway?] stations, "passengers go through a turnstyle and put their ticket into a machine that punches them before the passengers go on to the platform."

So it seems "punched" can be OK, too, depending on the train station.

Answer 2

Before you go on the train, you have to stamp your ticket. (not "stamped")