Overall, having previous experience was not very relevant to this position, besides the ability to write and research well. I would also recommend a course that covers current North American and European trade and foreign policy priorities.
I prepared by arranging accommodation, flights, and health insurance very far in advance. I also made sure to look into cellular phone plans, local personal identification cards and bank accounts as this all required a lot of time and information. I also applied for an international driver's permit so that I could drive while in Germany. I joined Facebook groups for people new in the city and familiarized myself with the job and surrounding city as well as I could before getting there.