...are two questions. When I was in high school, an English literature instructor divided the students into groups of two and assigned each pair a literary topic to discuss in class. He told us that his evaluation sheet for each presentation would be very simple and consist of just two questions:
1. Did they understand the topic?
2. How effectively did they get their ideas across?
Those two questions are ones to keep in mind before and during any presentation, in or out of school.
For solo presentations, there's a more direct way of phrasing that first question. On a presentation checklist my world history teacher passed out to everyone, the first question read, "Do I know what I'm talking about?" Presentation preparation doesn't get more basic than that.