I was directed to InternNZ via a Dutch internship program. They had good reviews online and looked like they genuinely wanted to help you get an internship that fit with the specific tasks you needed to do.
It was based in New Zealand but also has the ability to find you an internship in Australia. At first, I wanted to go to Australia but after some research and interviews, I decided that New Zealand would be better for me. InternNZ helped me with finding a good internship abroad.
InternNZ helped me organize everything, helped with getting me set up in Wellington and gave me loads of tips about phone data, bank accounts, and all necessary items. My school doesn't normally provide internships abroad so I organized everything with InternNZ.
Make relationships with everyone in the office. It may sound silly but it will make your day go smoothly. Sitting at a desk can be very repetitious, so to have someone to talk to every now and then can really uplift your day,
It really depends on what kind of internship you are doing. If you are doing an engineering internship prepare yourself for having to wake up around 6 o'clock. Also, prepare yourself for working more hours then you are used to. In New Zealand, it is very normal to work at night or on the weekends. You will also be amazed by the beauty of the country when you choose an internship that allows you to be outside, so definitely be on the lookout for an internship where you get explore outdoors.
My biggest fear was not making any friends while being abroad. I chose to go and live in an apartment with two roommates that were also interning abroad. The came to New Zealand alone as well which meant they also had to find new people to hang around with. New Zealand isn't very different from the culture I am used to so that was easy to get used to.
Arrive in the country a few days prior to starting your internship. This will help you get used to the country, and if you are far from home, to get over the jet-lag. Break down your budget into different categories. For example, trips, pocket money, apartment, going out, etc. Take the time to really enjoy the country -- go on trips and plan them ahead because before you know it you will be on the plane flying home.