Losing weight in these areas?

I'm 14 and I'm pretty sure I'm a fairly decent weight (5 foot 5 and around 120 lbs). However I've developed some fat under my chin so when I'm laying down or looking down it becomes visible. I'm kind of self conscious about that and my thighs. Would eating a more balanced diet and getting more exercise allow me to lose some of the fat there? I wasn't sure if it was possible to lose fat near your chin that way or not... I'm also aware of the fact that you can't isolate certain areas for weight loss