I don't want to discourage you, but your recruiter lied to you. Your lack of work history is going to be a real problem for you. All of the conductor trainees that I've met on the NS are older, with long stable work histories, most of them managers and supervisors.
Keep in mind that the railroad is very serious business. The NS in particular, is a <i>very</i> serious company.
You have to think like the railroad -- As a conductor, you are in charge of the crew and everything that happens on or to that train. <b>It's your train. You are 100% responsible for everything.</b>. Can you handle that? Even an empty train is worth millions of dollars. A loaded train can have anything on it, including nuclear material, hazardous material and military equipment. If you screw up as a conductor, you can literally kill thousands of people and cause billions of dollars worth of damage. Would you put you in charge of that?
What the railroad really wants to know about you is: Will you show up for work? Do you have leadership ability? Are you responsible?
How could you best present yourself to convince that railroad that you'll show up for work and be responsible in your duties?
I doubt you'll get past the initial hiring stage, but if you do manage to actually get and interview, tell them you have an interest in rail transportation and that you are very serious about a career with the railroad.
I hope I didn't sound too harsh - best of luck!
-r