Idk where u are from but I’m from Ohio and we have fun shows which are little shows with stupid things like we have some speed show stuff there like poles, barrels, down and back, and ball race we also have horsemanship and showmanship classes and fun little things to do while riding like one time u had to canter to a barrel get off your horse and get on your hands and knees crawl around the barrel get back on your horse then canter back to the gate these shows were my first and boosted up my confidence u can also join 4-h and compete at your local fair I do this too and I’m starting to branch out to local shows that have harder competiton
Start with small shows in your riding school. You will start competing against people you ride with which will make you more confident. Since the environment is familiar your will feel more confident too. After a few of those shows ask your instructor to help you sign up at a show outside of your riding school.