I believe the training either takes place in Crewe or Polmadie. The distance from the depot you've applied for does not determine where, though I believe trainees/apprentices will be prioritised for Crewe placements. In either case, Avanti will sort out the logistics for you since you're an employee, so all they need from you is to start getting used to commuting or being away from home for a decent period of time. I think, given the scarcity of the job opportunity combined with the good job security and high salary, it's not really much to ask in the grand scheme of things.