Improve my singing voice

I’m in my high school choir, and I’m constantly learning new things about my voice. I really want to go for a Rachael Yamagata kind of style, I think it would suit me. I barely have time to practice since I live with my mom and dad and two sisters with barely any privacy, but I think practicing in the car helps. I’ll be in the choir again as soon as school is back in session (something I’m not relatively looking forward to, but hey, at least I’ll be a senior).

I’ve had singing lessons before, but I definetly think my voice can be more powerful.