Passport
It goes without saying, or should, but if you are travelling internationally, you need a passport. It should be valid for at least 6 months past your return date. Some countries won’t let you in if your expiration date is less than 6 months from entering their borders.
Look after it!
Travel insurance
There is a saying: if you can’t afford travel insurance, you can’t afford to travel. It’s just plain rude to expect people to bail you out, be in your government, go fund me or friends and family, if you get sick or something happens and you need to get home pronto. It should be a part of your budget from the start, but do shop around as there are many providers in the market. Compare the market is a good place to start to find legitimate insurance providers, with a range of policies to suit needs and budgets.