I did my speaking last year and got a distinction, finding a topic should be relatively easy with so much going on right now, perhaps try to link to them as there will be plenty of research ab it.
For expression and gesture, search up speeches by successful people on (I copied the way people on TED talk engaged audiences at the start).
Also, learn a few strong phrases about your topic and don’t use it until you run out of what to say.
Good luck and don’t feel stressed about it!