Being able to take part in the graduation defense first shows that your thesis or design has basically reached the current academic requirements. So be confident and don't be nervous. I just finished my master's defense last week. I don't think it's too difficult, but there are a few points to pay attention to. First of all, I am familiar with my thesis, and I know the characteristics of my thesis or design. Secondly, don't be nervous when answering the teacher's questions, be confident and answer as comprehensively as possible. In addition, the clothes for defense should be formal, which will give the teacher a better impression. I was defending my thesis, and the teacher asked me the purpose, method, innovation and future prospect of my thesis. I think this process is not too difficult on the whole, so we must be confident. This is my opinion, I hope it can help you.