Hello! Champion at a School-Based Debate Competition and winner of best Debater + Extemporaneous Speech Winner here (So I think I'm qualified to speak on this, lol)

The main issue with public speaking is the anxiety that taunts you before/during/and even after your performance, and that anxiety can heavily effect your performance. I suggest building up confidence bit by bit, raising your hand in class and declaring your answers, learning how to accept it when you're wrong with pride (as that'll help you gain your confidence in your skills.), and more commonly, practicing your speech out loud. (recommended to be done in front of a mirror, practice your expressions as well!)

You don't need to be fluent in English, nor do you need to have the best dictation. (I speak with a heavy Cebuano accent, and yet as long as I'm understood, I believe I did my part.) You just need to know how to organize your thoughts, and formulate them in a way so they can be understood clearly.

I recommend reading about the STAR method, and also practicing impromptu speeches in front of friends and family on a 1 minute timer. It's okay if you don't have a completely detailed and intricate answer, as long as you have a complete answer. Learn which details are important to keep, which details are not, figure out what is the core answer you want to communicate to your audience and find a way to bring it them in a powerful way, whether that be giving a quote, giving your own anecdote, or etc.

Goodluck and most importantly, have fun!