Just stay calm, be confident dont let urself down by just knowing the audience number. I have had countless presentations & seminar, some went well and some didnt. I prepare well, take notes on how i have deliver the speech and use subtle amt. of hand guesters for stressing some points. I would want you to walk up to mirror and deliver speech as if you're presenting right now, take as many tries. Note which words u stutter and where find out the alternate synonym if u could. Appreciate, the effort u made in joining this community to ask which means you want to be improve yourself. Happy learning & become a great person.. 😊