@star - first the greeting ( how are you, what's the topic and why do you want to talk about that) - then a short explanation of the structure of the talk (how long, what kind of structure to expect, what are specialties to look out in your presentation) - sometimes people like to talk about why they are qualified to hold this talk a this point, but idk - explaining the problem or story that gets answered with the explaination of your topic in the ems of the talk - then coming explanations about stuff, that needs to be known before the actually topic can be understood (here you should have some knowledge about what people you are talking to already know and don't explain that again.) - the talking your actual topic - then allow questions from the audience - then good bye and thank you