How to find your sound as a singer?

I'm 14 years old. I'm a good writer and i want to be a singer. I know it can't just happen I understand that I must work at it, post videos on youtube, get my name out there, etc. It's become difficult for me to write songs because I have trouble finding a rhythme that I like and it makes it even more difficult that I don't play an instrument. I know, i should play an instrument, but I don't know what genere I'd want to sing/write songs so how do i choose an instrument? I'm trying to teach myself how to play the keyboard, but I've realized that may not be my sound. I'm still going to learn because i can't hurt, right? Anyways i was wondering if anyone had some helpful suggestions as to how I can find my sound as an artist. Thank you(: