Almost everything that goes wrong on a first international trip happens in two windows: the 48 hours before departure, and the two hours after landing. Preparing specifically for those windows is more useful than general advice.
Documents
Check your passport expiry against the destination's rule, not against the trip dates. Many countries require six months of validity beyond your arrival date, and airlines enforce this at check-in. Visa or travel authorisation requirements change, so check the destination's official government source rather than a blog, and check it again a month before you fly.
- Photograph your passport and store it somewhere you can reach without your phone
- Print one copy of your accommodation booking, immigration officers sometimes ask
- Check whether your destination requires proof of onward travel
Money
Tell your bank you are traveling, or at least check whether they need to be told. Take two cards from different networks and keep them in different places. Withdraw from bank ATMs rather than standalone machines in tourist areas, and always decline the conversion offered by the machine, which is called dynamic currency conversion and is consistently worse than your bank's rate.
The arrival window
Know before you land: how you are getting from the airport to your accommodation, roughly what it should cost, and the address written in the local language. That single piece of preparation removes most arrival stress. If you land after dark in an unfamiliar city, pay for the simple option rather than the clever one.
Phones and connectivity
An eSIM bought before departure is now the simplest solution in most countries, and it works the moment you land. Download offline maps for your destination city. Screenshot your booking confirmations. Assume you will have no connection for the first hour and plan so it does not matter.
Insurance
Travel insurance is unglamorous and occasionally the difference between an inconvenience and a financial disaster. Read what the policy actually covers for medical treatment, and check whether it excludes activities you plan to do, such as motorbike riding or hiking above a stated altitude.
Expectations
You will be tired more than you expect, and you will see less than you planned. That is normal. The travelers who enjoy themselves are usually the ones who booked less. Leave one afternoon completely unplanned in a week, and use it however you feel on the day.
One last thing that nobody mentions: write down where you are staying on paper. Phones die at inconvenient times, and a piece of paper in your pocket has solved this problem for a century.
Read the seasonal guide for your travel month before you book.