For new speakers there will be a temptation to learn your presentation word for word. This will never work unless you’ve practiced giving it so much that it looks and sounds completely natural.
Remember that you’re giving a presentation, not delivering a Shakespearian speech. And remember that the presentation is not just the words, it’s also your energy and voice: the way you bring it alive.
Very occasionally you may be asked to give a presentation where the words are very important, such as in a legal setting or when you’re speaking someone else’s words. In this case, you will want to read out your presentation. But this is rare.
Great speakers will know their presentation so well that they can give it without notes. But this takes some time and effort. Any great speech you have heard has, almost certainly, been given many times. That’s why it seems so good: the speaker is practiced in delivering it.