Job interviews can be both eye opening and stressful at the same time. Quite an important judgement has to be made often after a mere hour long chat. That's why interviews are filled with probing questions like what are your weaknesses, what are your life goals, what would you change in your life, etc.
Because they cannot get to know you right away, interviewers use challenging questions to figure out your values, belief system, and get a general idea of your personality. Like many others, I never liked these psychological questions. I tend to overthink the answers, and I always end up digging my own grave.
One of the best tips I ever got was trying to practice in front of a mirror, and even doing a video recording. That way you can see how you come across and refine your answers over time.
After the interview, you'll have time to ask the interviewer questions. You might want to skip these silly questions to avoid embarassment.