Hello Geakoudaung35
It is impossible to know in advance if the seats are facing forward/backward because the composition of the train is not fix. Sometimes the car #1 is at the front, sometimes at the rear of the train. But, if free seats are available, it is allowed to change and choose better ones. You will find on displays what seats are occupied and what seats are free.
In Switzerland you have usually enough seats in the trains, but it can happen that you must stand at peak times.
Kind Regards
Danhiel