I’ve never found a way to not stutter. Instead I’d recommend going into it with the mindset that you will stutter and that it’s okay if you do. I like to preface speeches by telling my audience that I stutter. Most people are kind and understanding. The act of telling my audience puts me at ease. Most people haven’t ever been in our shoes but they can empathize. Prepare your speech and practice. I find that not knowing what you’re saying causes unease which compounds the issue. It took me a very long time to accept my stutter. I missed countless opportunities because I hid from them. I regret it. I’m glad you’re taking the initiative to do this speech. Take as many opportunities as you get.