Your diet will be your success or your failure to achieving a non-fat lifestyle, but that is exactly what it is ... a lifestyle. You have to change the foods you eat, you have to change how often you eat, you have to ... change!
1) Formulate a diet. This diet will be based on the goals you set for yourself. You want to lose weight. You will need to calculate the calories you are going to eat, and make sure those calories are coming from the right sources (protien, carbs, fat). This may seem complex to start with, but it is fairly simple, and after you start doing this you will see how easy it is to add up what you are eating and what you can eat.
2) Build an exercise routine. The most important things about an exercise routine is to make sure you are working out safe and properly. Make sure you know how to perform the exercises correctly and start off light, once you master the technique then you can slowly add weight etc to increase the effectiveness of your routine.
3) Healthy options. Drinking water, a multi-vitamin, etc are all things to consider when trying to change ones lifestyle.
4) Realize that you can achieve what you want. Thousands of people change their lives every day, and it all starts with one sentence "help me i dont wanna b fat for whole of my life".
You won't be fat the rest of your life, you can see the person in the mirror you want to. You have already taken the first step! Congratulations.