When planning a rail trip, most tickets can’t be booked more than 30-90 days in advance depending on the country and carrier. Enter a date within 30 days of today to see general travel times and ticket fares – they rarely change much within the calendar year.
Long travel day? Many European airports (and train stations) have clean public shower facilities. Ditto for airline lounges in the US.
In most of Europe, seat reservations on trains are optional. Buying the ticket is just paying the fare. You can then choose to pay extra if you want to choose and reserve your seat in advance.