I'm guessing you would like advice on how to go through an interview in English. My advice is simple: just speak naturally. Yes, you will make mistakes. And by practicing, you will eliminate a lot of those errors. Realistically, however, you can't eliminate every speech error. But that doesn't matter! What matters is that you speak fluently and confidently. English speakers are generally accustomed to meeting people with another native language. Outside of grievous mistakes, we can generally understand what your trying to say.
What does that mean? Your interviewer won't be judging you on grammatical mistakes. They will judge you on confidence and competency. As much as every mistake may bother you inside, constantly going back and correcting yourself will be much worse than just pushing forward. Stay confident, speak at a good pace, and don't constantly correct yourself! Your interviewer will overlook the small mistakes you make in the process!