Weightloss

Hi everyone. I'm not really at a bad weight, I'm on the chunky side, so I'm wanting to tone up some and maybe lose a few pounds. I've been doing squats, sit ups, crunches and little other excersises. I've cut out pop for the most park (I'll take a drink every now and then, yesterday I had a glass) and have been drinking water and juice. Any advice? My mom told me to start counting calories and I just donoaded MyFitnesspal. Any advice would we greatly appreciated, thanks! :)