In the more general interviews, you are asked things about your skills and background, particular sex ed interests, etc. One big thing that they need to see is if you have some form of health education experience, whether it was a former job, volunteer gig, internship, etc. One of my interviews was a "tell me about a time you..." so come prepared with a few situations in your experiences that you handled well.
For the presentation, you give your presentation, but since the department members are asking you questions, you need to be quick on your feet and engage with them. But they love asking difficult questions and trying to derail you. So be able to answer their questions and don't detour too hard. When asked value questions (is it normal to do this? etc), follow a some people do this, other people do this, and you have to decide what's best for you kinda thing.