Follow the same food choices and exercise regimen from the camp. The only difference is you will be depending on yourself to motivate you and not a counselor. You'll also be depending on yourself to portion control the amount of food and not a cook in a cafeteria.
If you have some friends or siblings who can go through the routine with you, that will add some competitive motivation and support.
If you have a friend with a mother willing to teach you how to cook healthfully, take some lessons from them to learn about nutrition and how to add flavor to your food without adding lots of fats, salts and sugars.