Does your school have a choir? Join it. And then you will be singing on a stage with a lot of people who love to sing like you. That’s the only way my friend will sing on stage. But, I don’t have stage fright, except in oral reports so it doesn’t bother me.
You shouldn’t put a video on Youtube. A hundred things could go wrong. Your voice might sound weird. The camera could break. Anything. Also if your school doesn’t have a choir, join the musical for find a musical in your area.