You need to change your diet a bit and do some regular, gentle exercise. If you are overweight, a great exercise to start with is swimming. When you are swimming, the water supports your body weight, so there is much less strain on your joints. Swimming doesn't burn many calories at first, but it makes your muscles stronger. Walking is also a great way to start losing a bit of weight. You will quickly find that walking up hills is very tough! You can make walking more effective by wearing ankle weights.
As for for food, there are four simple rules. (Yes, the are RULES!) Eat proper meals instead of meals and snacks, choose low calorie foods, drink plenty of water and avoid certain foods completely. Three proper meals a day, bulked out with lots of fruit and vegetables, and about a litre* of water a day should be around 2500 calories. Keep eating like that and doing gentle exercise every other day, and soon you will start losing weight and will be able to start running. It's very hard for the first couple of weeks, but get much easier. After a while, you won't feel like you are missing any foods and you won't feel like your exercising. (* Some people will be shocked that I said 1 litre, and not 2 or 3. If you are not getting lots of water from your food, you aren't eating enough fruit and veg. That simple!)
As for for food, there are four simple rules. (Yes, the are RULES!) Eat proper meals instead of meals and snacks, choose low calorie foods, drink plenty of water and avoid certain foods completely. Three proper meals a day, bulked out with lots of fruit and vegetables, and about a litre* of water a day should be around 2500 calories. Keep eating like that and doing gentle exercise every other day, and soon you will start losing weight and will be able to start running. It's very hard for the first couple of weeks, but get much easier. After a while, you won't feel like you are missing any foods and you won't feel like your exercising. (* Some people will be shocked that I said 1 litre, and not 2 or 3. If you are not getting lots of water from your food, you aren't eating enough fruit and veg. That simple!)