Opera singer in training?

so i am 14 and i sing bass throw soprano and i would like to sing opera. Singing is my passion and i would like to sing tenor like Andrea Bocelli. I have never sang opera professionaly but i have proformed live with Barry Manilow, so im not afraid of singing in public. All i would like to know is how should i go about singing arias, and how i should train my voice to do so.