Bexuyett70 Hello Yokoo
Q1: The same way as you probably already bought your P2P tickets: Look up that particular IC3 connection and go to the ticket choices: There you should find “reservation only” as one of the ticket options.
However:
You won’t need a seat reservation in that train on a Tuesday at that time of the day. The 1st class coaches will most likely be almost empty, and 99% of the other passengers won’t have a reservation neither. (And nobody will have a reservation on the IR38 train anyway)
Q2: Exactly. Just another reason why a reservation doesn’t make a lot of sense in case you would miss that 09:38 IC3, as reservations are neither refundable nor exchangeable.
Q3: Is possibly the birthdate year correct, but month and day are reversed on the tickets? Note that in Europe we use the dd.mm.yyyy date format, not the “american” mm/dd/yyyy format.
So should this be the reason for the “changed” dates, then there won’t be any issues during a ticket control, as this mishap could easily be explained and the correct dates determined.