Use quotes if you have some. Speak loudly, clearly and in complete sentences. Silence too, can be a powerful tool. A few seconds to stand, reflect and gather your thoughts can work as part of your talk. If you make a mistake, pause, regroup, put it behind you and continue your talk.
Audiences are quick to judge but are also human and forgiving.
You will learn something from every speaking engagement, gaining confidence in your abilities. You may want to learn more about public speaking through books from your public library. You will often think of ways that your presentations could have been better and wish you had done things differently. That is the way all great speakers begin. Feedback is appreciated.