Hello and welcome!
The thing I do mostly, depending on times etc, is visit the nearest pub whilst waiting for a train. Normally if I'm waiting for train an hour and over.
As for what you do on a train journey, sit back, relax and go to sleep! That's what I do when on these modern units getting from A to B! If I'm not sleepy then I just look out of the window and watch the world go by!
If I'm on a railtour then I sit back, relax and enjoy the thrash!