Working the voice

I'm working my voice.
I'm working on my voice.

I have just arrived from my first ever choir rehersal as I've joined a local choir to learn/enhance my vocal abilities. It was easy, as expected, but I'm sure there will be a lot to learn regarding so many aspects. The first studies were on one of the best portuguese maestros, Fernando Lopes Graça.

I still don't like my voice.
I hope to learn how to minimise that.