1. There is no need to activate your pass or travel days in advance. It's even a bad idea because if something happens after validity starts, then you can't cancel them anymore.
2. When you tap on Show ticket, the app wil normally show the ticket for the current date or (if pass validity hasn't started yet) for your first travel day. Above the barcode though you can change the date and see the barcode for other days.

Thank you for the answer.

Re point 1- would it matter if you didn't cancel a journey? Could you just add a new one?

Re point 2 When I click Show Ticket  (Pass does not start until March 9) I do not see the first travel day therefore no bar code.  This concerns me greatly.  I have reservations  for some journeys or part journeys printed off but no evidence that I have booked other trains

1. You can always cancel/delete a journey and add another one. However, you can't cancel a travel day anymore after the validity of that travel day has started. Likewise, you can't cancel pass activation anymore once the validity period has started.
2. Please first check for any any app updates. You should have app version 28.2.0 (go to More, scroll to the bottom).
   If that doesn't help, then please post a screenshot of what you see when you tap on “Show ticket” (wipe out any personal details).

The update has done the trick 

thank u