I don't really know much about trains so I need some help I'm going to speak to someone at the station tomorrow anyway, but I've booked off-peak return tickets for an earlier train than I actually needed. The website won't let me change the times. Since it's off peak, do I have to take the 7:15 train or can I catch the 9:45 train instead, with the same ticket?
Does your ticket say booked train only, is there a time on the ticket for when you travel, if so then yes you do have to take that train as your ticket would not be valid on other trains even though it means getting up earlier than necessary.
It is possible to change your ticket however there is an admin fee (or whatever name they actually call it) of £10 per ticket so it probably isn't worth changing the tickets. But talk to the staff at the station too