First thing you have to consider is who your audience is. The content of the lecture and its delivery should be determined by the audience it is directed toward. General population, educational presentation for young musicians, music teacher conference, general academic audience, a specialist academic audience that knows a lot about the topic you are presenting, etc. Are you being graded on this (doing this for school)?
Go listen to a number of lecture/recitals, they don't have to do anything with Appasionata. Gain an understanding and perspective of what it means to be an audience member in these presentations.
Be focused with your delivery, you don't want to turn the presentation into a data dump. Present the information, don't just unload it in front of your audience and expect them to connect the dots. As a presenter, it is your job to present the data and illustrate how all these data points connect, compare, contrast, agree or disagree with each other. It is your interpretation of the data.
If it is for a general music appreciation audience, include things like: historical context, what was going on in Beethoven's life when he wrote it, what to listen for to gain a better appreciation for the work.
If it is for an academic audience, I would treat it more like a paper presentation or journal submission. You would want a clear research topic. You would be dealing more directly with specifics related to your research topic. You would be more free to use technical language and lingo understood by specialists in the field.