From my current experience and partially beyond the technical realm (though probably out of scope for your question):

• Adapters / multiple socket outlets for your devices
• Maybe a second (portable USB-) screen
• 2nd phone/sim slot for any MFA/SMS sent to your current number, since you will probably have a local sim card in your current phone then
• Read up on culture shock theory. There will probably be an emotional low point a few weeks into the experience. Then you know what it is and that it will likely pass.
• Remember that you are working abroad and that your free time is limited. There is a challenge to set up new routines for your daily life (like where to shop, what to cook, …). It takes a while to really arrive in a new place.
• Have something to do after work and after sightseeing. I am happy about my exercise routine. But I also recommend having a hobby for socializing.