So first of all, I suggest that you interview on time! This is more important than anything. If you can bring a watch, you can also show your good sense of time.
Second, you'd better prepare an English self-introduction in advance and memorize it. It should cover the most basic information: name, age, graduate school, working years, where you are working now, what position you hold and the reason for looking for a new job. In this case, if he asks you to introduce yourself, you don't have to panic. Even if he doesn't ask you to introduce yourself and ask some related questions, you can blurt it out.
Third, the most frequently asked questions by foreign bosses. One is your work experience, such as what is your job content? You should summarize your work concisely so that he can understand it quickly. Then, if you have any outstanding performance in your work, you can also highlight it. Why did you choose their company? You can consider this. In fact, Germans are very humorous. Even if you say you want to earn more money to buy a house, I'm sure they will understand. Some people think they will ask the pros and cons, but I think the general domestic leaders will ask more questions, but the more answers they prepare, the better. Don't go into too many details about the shortcomings, just say irrelevant ones. By the way, I was also asked, "Do you think you have any information about the results of this interview?" In fact, we China people are very modest. Just like others praise us, we often say "No, it's not like that". But in front of foreigners, please be confident If you want to be modest, just smile and tell him that you have a lot of information to get this offer! Whether you have a bottom or not, yes!
Off-topic, since I am a German boss, I will interview you in English, but my mother tongue is still German. Therefore, I suggest you attack two sentences of German, which will leave a very deep impression on the boss! I recommend two. One is to say: Guten Morgen, which means hello. Besides, when you leave, you can say: Auf Wiedersehen, goodbye. It doesn't matter if it's not standard, at least it highlights your courage. I tried it, and it worked well. I hope your interview goes well!