I’m non binary and I don’t know how to tell my teachers and school, any ideas?

Maybe you can first identify one teacher that you connect particularly well with, or that you believe to be supportive of LGBT realities. You can open up with this teacher and tell them about how you started questioning your gender, how you feel about yourself, and how you came to the conclusion that you are non-binary. Make sure they know what it means to you and what you need, for example how you wish to be addressed. Maybe they can help you breaking the news to the other teachers as well.