Help me design a weight loss regimin?

Okay so I am 5'8/5'9" and 178 lbs. Im not obese looking but i look like i have extra baggage. Im a size 8/10 and I want to be a 4 by summer so this spring i wat to lose 48 lbs. I know that may not be that obtainable for some of you but i know i can do it. can i have excercise tips? That is my big thing. i dont exercise the right things and i have no motivation. and i have found low carb diets work best for me...any tips? Im a high schooler so i need ideas on what to bring to school that is carb free. Thanks!