Doing a speech is very hard especially if you don't know how to memorize it. For me it isn't that hard.Step one is to reread the speech.The way that I reread my speech is different I don't read it word for word or else it will strain my brain and put more pressure on myself so instead I would just reread the first half two or three times and then move to the next part of your speech and memorize it three or two times.
Step 2 Don't stress
While memorizing your speech you have to have confidence.You shouldn't stress this also goes hand and hand with not reading the speech word for word.The more you stress the more you start to forget things.To ovoid stress you should meditate,think calm thoughts,breathe in and out and conquer the world.Pretend you are your favorite role model.
Step three Overcome stage fright/Anxiety
While your going over your speech I would suggest that once your comfortable enough and have build up a lot of confidence you should perform your speech in front of your family,a camera or your friends.You should also try doing this without your paper if you memorized it well enough.If you have anxiety get a stress ball or prepare yourself by enhaling and exhaling and think positivly and calmly. And once presentation day comes conquer the world make your voices be heard project sound and make sure you focus on your message the message is key.