Force the air up from the bottom of your belly, pushing your diaphragm wall outward in front, on the sides, and in back, leaving your chest, neck and face completely relaxed. This is the beginning of beautiful, flowing tone for any style of singing. Accurate pitch requires maturity and control over the voice. Listening is the basis of all musical skills. Learning musical notation is much easier on an instrument.
Piano is an excellent beginning instrument.
Developing the voice is a challenging, life-long process. Don't force your voice. If you want a solo career, find a professional teacher who works with teens in all vocal styles. Your voice teacher should have a university degree in vocal studies and when you are ready to choose a college, look for one that offers a music major. The skills you learn through singing will enhance your life and the life of your community.