Introduce yourself.
Introduce your presentation.
Tell the audience who you are and what you do. There will always be someone who can’t remember your name. They will not be focused on what you are saying until they find out.
Tell your audience what you will be talking about; How long it will take. Whether or not to hold questions until the end, or to feel free to interrupt you while you are presenting.
Give them some positive expectations. (E.g. “For the next twenty minutes, I am going to show you how to increase productivity by 25%”.)
There is a very old adage about presenting that says: “Tell them what you are going to tell them; tell them; then tell them what you told them.” You will be helping your audience and yourself.