Thank you for posting your question here. Well, there are many things you could do in order to improve your public speaking skills. Two things I really want you to focus on as a beginner as of now and this really helped me when I was starting also is;
Grab every opportunity you get to speak at your level. The more you practice speaking will help improve your cause. Don’t think too much and just go for it.
And make sure the content you have for speaking is good enough. Initially, chose the topic that you are very good at....Good Luck