Have solid answer to questions, product market fit,etc. I'm not sure what they will ask here.
Find all available and relevant presentations on internet and take any idea that applies and appeals to you.
Base your presentation on data that you can backup. Try to show that in interesting way where you balance between too much optimism and reality.
Be ready to be thrown curve balls at you dismissing your idea as naive or doesn't hold true. You will be asked hard questions. Learn how to handle them.
Ask someone to attack your idea and try to get better answers to handle such questions with data and story and whatever that can break there mindset.
Be confident and All the best!