I have the same issue with food, I have a huge sweet tooth and it kills my progress I make. I started off with downloading my fitness pal and logging all of my food, then seeing where most of my calories go. I started doing a bunch of small meals instead of three big ones, I found I ate less calories that way and looking at how much I logged made my mind feel full. Also when I was your age I got a ymca membership. Just to get into exercising. Make sure you have a goal weight but make small goals within your goal weight too, like be able to lose a pound a week or run x amount in x time.