First off, talk to your teacher about this. They may be able to offer you an alternative project.
Second, if you are going to have to get up and talk, just keep in mind that most of the audience for any student class presentation is mentally tuned out because they either are terrified about going next or they just can’t stop thinking about that girl in the next class. It would take a miracle for your presentation to actually be remembered by them.
The oldest suggestion for dealing with fear of public speaking is to picture the audience naked. This works unless there are sexy people there, in which case you will forget what you were saying. Instead, just pick a single person in the audience, and explain your topic to them. Ignore the rest of the room (they are probably ignoring you), and just speak to that person. It can be the teacher, or a person you think would be interested in your topic. If you don’t have any other ideas, just pick the least-attractive person in the front of the room (because picking a cute person can increase anxiety!) and talk to them. Don’t even bother looking at anyone else; you might get docked a couple of points for not making much eye contact, but you will make it through the speech.
Bring a bottle of water with you and take a couple of sips before you get up to speak. If your presentation is more than 10 minutes, you can bring the water with you and take a sip if you need a moment.
Last piece of advice — take normal steps to manage anxiety. Get sleep the night before and avoid caffeine the morning of the speech. Caffeine and other energy drinks raise anxiety levels. Get exercise if you can, because this reduces anxiety and boosts energy and focus.