Let’s see. I have 10+ years of living/working/studying abroad. But this was in Asia.
For taxes, there was a minimum that I needed to make. If you don’t make that amount, you don’t have to do your taxes. That was me. Though a lot of people told me to do it anyway for retirement stuff.
But I did have my gross income taxed normally in the other country. So, since you and your girlfriend are unmarried, consider your income separately and check the US amounts that I forgot.
Moving abroad is hard. You can’t take heavy things with you. Even equipment for hobbies like biking, scuba, etc. It becomes a burden and takes up space. It’s like a vacation but with a lot of knickknacks that you won’t find abroad.
Working abroad will be different. Even in the same country, every job had a different work environment. Now it will be more difficult because they will talk about rugby or chasing kiwis for fun or something. At least there is no language barrier and you can pick it up. But know that conversation starters like talking about your differences will only get you past the beginning. You still have to relate to these people somehow. Hopefully they are nice.
Finding a place from the US is difficult! A lot of renters still don’t use the internet because they are old people. And a lot of places on the internet are terrible and you can’t find out until you get there. I recommend this, choose an apartment that you think is good. Hopefully it is. But definitely plan to move. Walk around residential back alleys because people sometimes put up signs for renting. You could find a real estate agent, but owners normally try to do things themselves…This is a difficult topic because of so many things that can go wrong. Noisy area, mold, making contracts, breaking contracts, barking dogs, thin walls, etc.
Also, hopefully it is furnished. Because everything you buy will stay there after you leave. You wouldn’t want to bring furniture back to the US.
A child in elementary school…I have no idea how that will turn out. Talk to their teachers once a week in the beginning to make sure they are adjusting well.
2 dogs. Uh oh. Depending on the airline, they could really be harsh on these animals. Medium size will not be allowed with passengers so into baggage they go. Do some research because I’ve heard of animals dying in the heat from being left outdoors while baggage is being transferred between planes. I had reptiles and I was so worried they would freeze or overheat that I payed a specialized service (very expensive) to make sure they were taken care of. They brought very insulated packages and handled the airlines independently.
Also, a lot of landlords hate pets. So that will limit you a great deal.
Work applications were nothing special. You either have what they want or you don’t. As in any country, interviews and calls are a hassle that need time.
A not so important note. Couples that move abroad might break up. It is a real thing I’ve seen many times. It gets ugly. There was this one couple that had little money and hated each other so much but didn’t have enough to move out and didn’t want to break their work contract to go home. Imagine living with an ex and everything that can happen from that. Glad I never experienced it. Good luck!