1.Visas
Check online whether or not you need a visa before traveling to avoid problems later.
2.Money
Learn about the exchange rate and also get a card with a 0% foreign transaction fee. This will cut on costs in the long run.
3.Travel adaptors/voltage converters
Check out here: https://www.110220volts.com You will find everything you need to have a trip without problems.
4.Travel insurance
Travel insurance is one of the most important things that you can purchase for any international trip and it is something that you should consider very seriously.
5.Research
Read up on the destination! Make a list of the must-sees and do not lose a thing!