I want to sing

The title is just a beat I’ve been tapping with a pencil on the table. Just kidding, it’s random. Well, to the point. I am 14 years old (YES) and I used to sing in a choir. Once I did a solo when I was 7. I kinda messed up but it was cute ‘cause I was little. My voice back then was good, because I was small. It sounded cute. Now, my voice is grown up and I can barely reach high notes without sounding weird. I’m on-key, and I can reach them, but it just sounds weird. I just want to get up on stage and sing a song. Because I’m an actress, and I’ve always been in my school’s productions, I want to be in this one too. I’ve always been one of their faithful actresses, and I want a bigger part now. One problem – it’s a musical this time. So I’ve been searching for tips, advice, and confidence. Help. :D