Weight loss tips?

I'm 17 f, and I weight about 120 pounds, 5'0. I'm a bit chubby and have squishy thighs and have a stomach that plunges out...... I dont exersize at all. I want to loose weight for my next school year, so I got lots of time. I want to loose weight "easily" but I know there isnt any real easy way to loose weight..... SO. I want to do some little stuff that'll contribute to my weight loss if you know what I mean. Like, drinking lots of water everyday (carrying a water bottle everywhere) or using the stairs instead of escalators, walking to school instead of driving, etc. and even food choices. I don't eat healthy at all lol. I eat DQ everyday (because I work there full-time) and it's very temping. I eat a medium blizzard and fries each shift. so..... i know its not healthy lol. and there's not alot of healthy choices there too.... Im actually very suprized by the fact that I eat so many dairy queen ice creams everyday, but I'm not obese or even over weight.... what to do?