Not too fast, not too slow. Clearly enunciate each word but with a strong, yet not overpowering energy that shows confidence. Remember, no one on this planet it particularly smart or gifted when compared to everyone else. The foundation of modern western civilization is literally built on this principle (Thomas Hobbes) so don’t worry about saying something wrong or incorrect. If people are offended you can always sincerely listen to them and apologize if it’s warranted, so there’s no reason to not speak confidently.

Watch interviews with the Marvel movie cast. They all (except maybe Brie Larson) speak confidently from their chest. Those people are literally put under the most powerful media microscope on the whole goddamn planet where if they say something wrong they can literally go from being loved by millions to nobodies instantly. If they can speak confidently with that kind of pressure so can you.