Know your subject in and out. Anticipate questions and mentally prepare answers.
Know your audience. Read the room. If people start being bored, speed up and cut straight to the chase.
Practice your verbal skills in front of a mirror.
People pay closer attention to beautiful people, so try to improve your appearance if you can. Start working out, get a fresh haircut, clear up your skin, that sort of thing.
Find an online course on communications. There’s probably some free ones out out by accredited universities.
Study AP level English. Good writing skills and good speaking skills go hand in hand.
ToastMasters is a little culty but very valuable for public speaking.
Rhetorical studies.
Maybe look into Journalism.
Journalism looks like Education/Pedagogy but its not. Its info compression. People are busy, attention is finite and you are giving them just enough to stay relevant in whatever game they are involved in.
Education is not about compressing info. Its about delivering all the tricks in the book relevant to the subject from one mind into another. Sometimes metaphors required to aid the transfer. But the success of the teacher lies in how much info is transferred over.