Be professional, and strictly safety minded ... most RR'ers do not like "Rail Enthusiasts" and "Foamers" ... they take their job extremely seriously, come to work, do the job safely, and go home again at the end of their shift, and generally do not railfan.
Most RR'ers do have an avid love RR's ... but be professional, serious & safe !
Be prepared for complex all day testing, and examinations.
Also prepare for your professional responces when asked: "
Why do you want to work for the RR" ?
If you mention, Example: I run "Trainz" simulator, and "I want to be able to run the big Locomotive" they will have second thoughts.
A good responce would be: "I know that I am perfect physical condition, and am highly able to perform the specialized job skill with the highest degree of safety, and I am looking forward to extensive training, job title advancement and a lifelong career.
When asked about smoking, drinking ... Say absolutely NO !
Do not come in smelling of Tobacco ... and use Binaca minty clean breath freshener.
Drug urinalisys, and Tobacco blood analisys testing may be part of the follow up interview.
Be prepared to be bumped and relocated often in,
at least, the first 3 years, with little time off duty.
PS: Congradulations !!!