Am I going about my diet the right way?

I am 23 yrs old and 4'11 and I weigh 126 lbs. Im not extremely overweight but I need to lose at least 15 lbs to be more fit so I have started eating better. I have totally just cut out all fast food this week. I would like to know if I continue eating the way I have this week: breakfast then a small snack like a yogurt then a lean cusine meal for lunch a small snack in the afternoon like an apple or some melon or berries then a dinner like steak or pasta will this help me lose weight? Also I will excercise about 15 minutes a day. Im really trying this because I feel like not only if I do this for myself and my health my friends may try it to and be more cautious of themselves as well. Please help with any input.