Petite, small but so unfit

BeWhatYouWant07

Hello everyone,
First of all, I am introducing myself as petite and small because no one around me understands why I am trying to keep fit. I might not be overweight or wanting to lose weight, but I want to get a toned body. Underneath all my clothing, I do have extra layers of fat :-(
I started exercising (and drinking 2000ml of water) on the 1st Jan 2016. So far I have managed to do moderate exercises for 15 to 30 minutes daily. I do feel so much better. However, being so unfit, I am finding it really hard to exercise or not to eat junk ( easily available food)

Would love to hear from you.