Is it more important what you are saying, the information that you are transferring and the way in which you form it?
Or is it perhaps that a truly great speaker can make any information appear meaningful, packing it in a story and using all his assets to raise interest for his message?
Not to put down the importance of “technical” skills of presentation – voice, body language, using space etc.
But if you are wondering what to prioritize and where to start your learning from, I would definitely go for forming your content, providing structure and making sure that you have a clear, concise, impactful message.
Make sure that you know what you want to say, and notice that everything else is just a tool that will help you get that message across.
If you are not sure how to get there, check out some of the older posts that can help you achieve this:
How to create and deliver a great (elevator) Pitch
The presentation structure
How to transfer the message effectively