Well, on a rapid transit system, sometimes it's a conductor that makes the announcements and opens and closes doors.
Good for you! Your responsibilities  as a conductor will include: making announcements and opening and closing doors. Pretty simple, no need to be nervous.
I have got a new job! You know anything about conductors? Are you referring to the train crew member? Conductors are responsible for the aspects of operation and safety of the train that don't involve actually operating it. Well, my uncle got me the job. He did not tell me any of this! I am supposed to start tomorrow so was trying to find out info on it. What else do you know, deciding to be nervous or not...
The responsibilities of a conductor in North America and of a guard in Commonwealth English typically include the following:  Some rapid transit systems employ conductors to make announcements and open and close doors—as opposed to a train operator performing those duties.