Lose fat + tone up

Hi everyone, my name is Jen. I have been using my fitness pal for a few years but over the last week or so I have decided to take it seriously. I am half way through my second week of eating healthily. I have always loved the gym but my diet before wasn't great so now I'm hoping it makes a difference !
I'm 16 and don't want to lose lots of weight, just fat on my stomach. And from there I would like to tone up !
Jen x