If you want to lose weight, you have to be in a calorie deficit. This means eating fewer calories than you burn off.
You can reduce calorie intake by eating less, but eating less is really hard for most people, which is why I recommend swapping unhealthy, calorific food, for healthy low calorie options. Swap cake and biscuits for fruit, eat more veg and less pasta, and skip the oils. This reduces your calorie intake and means you shouldn't be hungry all the time.
You can increase calories burned by exercising more, but burning calories by exercising more is difficult. Even a hard workout a few times a week might only burn 1000 calories over the course of a week, the equivalent of 150 calories a day. It's also really easy to compensate for a workout by eating more. High intensity exercise also tends to burn glycogen or sugars in your body, rather than burning fat.
Instead, just try moving more. Take regular breaks from sitting down, walk to the shops, go shopping. Cook dinner instead of getting take away - it'll probably be healthier, and you'll burn twice as many calories than you would have done sitting on the sofa.
Whatever you do, it has to be sustainable. Crash diets never last and lead to weight yo-yoing which is bad for your health. Lose weight through your lifestyle, and you'll keep off the pounds.