Work backwards from the first fixed commitment
Start with the time when you actually need to be ready: at the completed stand, for example, or outside the agreed entrance. Before that you may need to drop off luggage, walk across the venue and register. Write down those stages separately. A train arriving at noon tells you little on its own about whether a meeting shortly afterwards is realistic.
Check the entrance on the specific event's website. A large exhibition site can have several access points, and its general postal address may not lead to the entrance your appointment requires.
Treat connections and the last leg separately
Do not judge a rail itinerary only by its total duration. A connection also involves changing platforms, handling luggage and finding a lift if you need one. A route that looks short on paper may be awkward with a heavy sample case. Check available station information and choose a transfer you can reasonably manage.
Allow separate space for the final approach: finding the correct exit, taking local transport, walking and possibly queuing. This buffer serves a different purpose from the connection time between long-distance trains.
Write down a second plan you can use
Save your booking and destination address offline. Also note whom you should contact if you are delayed. A short message with a realistic revised estimate is more useful than repeatedly promising to be there in a moment.
Looking up another connection in an app does not automatically make your ticket valid on it. During disruption, check the operator's instructions and your booking conditions before using a different train.
Avoid filling the entire first evening
After a long journey, an uncommitted hour before your first meeting may be more useful than one additional appointment. It leaves room to drop off your bags calmly, eat or test a presentation. The appropriate gap depends on your journey and the task ahead. One standard number of minutes will not suit every trip.
