Let's start off with some quick wins. If you have to stand up and give a presentation to a group of people, the first thing you can do is nothing. Just take two seconds. Smile, look at people, and you'll stand out as much more confident and comfortable than most speakers who just race into it. It also gives you a couple of seconds to reflect. calm yourself down.
Tip two, don't worry about memorizing, stressing try and read bullet points on a PowerPoint instead. Do what I do, cheat. Use a cheat sheet. The key is one sheet of paper, really large font. This way you can just put it down, never have to touch it. No one sees you turning pages, you'll look surprisingly confident and authoritative.
The third really big tip. Don't ever give any presentation until you practice. To start video these days, just use your own cell phones I don't practice in a mere waste of time. Practice recording yourself on video. Look at it. Keep doing it till you love what you see lots more to come.
Stay tuned.