Your vocal control is extremely important. You’ll learn to use intonation. The level of your voice says nearly as much as your words. You need to make sure you’re comfortable with your vocabulary. Don’t use words that you’ll stumble over.
It took me years to master orientated over oriented. I grew up with a learning disability and was terrified of using the wrong words at the wrong time but eventually learned not to use words until I thoroughly understood their meaning.
When you use dates, be sure that they are correct. If you use statistics be sure they’re accurate. And one of my real pet peeves is not giving the person the credit for a quote that created it or not using the quote accurately.
Be sure your presentation has the appropriate beginning, middle and end. And always deliver more than the perceived expectation. Content rules in the speaking arena. Don’t ever let anyone tell you any different. There are a lot of speakers who deliver a lot of fluff and are constantly selling throughout their presentation, don’t become one of them.