Just curious:
What is the topic of your speech?
At any rate, to do well, I would recommend:
1) Go ahead and let yourself be nervous and afraid!
In fact: be proud of your nervousness!
You're human. You're not a robot or an alien (that I know of). You're going to be nervous! That's just the nature of our species.
FOR EXAMPLE:
I did an FM radio show for 5 years (back in the early 1990's... just goes to show you how old I am!).
The first few months of the show I was so nervous, that it wasn't uncommon for me to literally vomit in the bathroom at the radio station, just before my show!
But then I stopped trying to hide it from my audience and made jokes about it.
One time I went on air, and confessed how much I loved radio, but that because I was new it made me so nervous that I barfed in the bathroom just before the show!
When I played the next song, my phone-line literally lit up with inbound listeners laughing at how my description of barfing and nervousness was funny, and they went out of their way to wish me luck, and told me I was doing a good job, etc...
So the audience appreciated and respected my honesty.
Things went a lot better when I was honest with my audience!
In fact, the later years went so well, and I had so gotten over my nervousness, that I would simply waltz in a few minutes before my show, completely unphased, then step into the booth, and hit the "Microphone-Live" button...
and just start talking like it was the most natural and normal thing in the world!
But I didn't get there immediately. It takes time to get to that level.
And until then YOU and EVERYONE will be highly nervous when speaking publicly. It's utterly natural. And it means you are a normal human being!
But ya... if your anxiety and nervousness gets REALLY bad, like it did for me at first, then you might want to use the same strategy I used... and say something to the effect of:
"Hi there everyone! I'm here today to talk about XYZ. But before I begin my speech, I just wanted to say public speaking totally freaks me out, to the point that I got so nervous last night that I didn't sleep well, and barfed in the bathroom a couple of times! But neverthless, I'm still here! My voice is a bit shaky and nervous... So wish me luck! Anyways... what I would like to discuss today is..."
2) Try to anticipate and imagine all possible questions and arguments that the audience might have against the points you make.
Even if the audience won't be interacting and asking question afterwards, by anticipating their questions you'll really connect with them.
For example:
"Now... I know what you might be thinking about that last point. Some of you might be wondering... XYZ... and that's a good question. But the answer is that ABC..."
3) Know and enjoy your topic!
If you don't really know your topic, and haven't done much research, then it will show.
The more research you do on your speech-topic, and the more passionate you feel about it, the more the speech will just naturally write itself!
In fact, people who know their topic intimately often don't even bother writing a speech.
Instead, they just write a short outline of the general topics and sub-topics they want to discuss.
And then when they're at the podium, they look at the outline, and just start talking!
(And sure... a few parts of their speech and/or jokes during the speech will be pre-written... but a lot of the other parts of the speech will just come straight from the heart.)
Conversely if you detest the topic of your speech, or disagree with the topic, then try not to give a speech!
Try hard to only give speeches on topics of great interest to you.
If you are not obligated to give a speech, then volunteering yourself to give a speech on a topic you don't like is essentially just making your own hell on Earth, for no good reason!