If you want to lose weight you will need to eat fewer calories than you are burning but it is important not to cut down too low otherwise your body will go into starvation mode. This means that your body senses that there is not enough food and will actually hold onto fat and all that you will lose will be muscle (this will slow down your metabolism).
Eat a healthy diet, plenty of wholegrains (oats, wholemeal bread and pasta, borwn rice), low fat protein, (not too many eggs, chicken, turkey, pulses like beans and low fat dairy produce) and a small amount of fat (mainly from nuts, seeds etc as these help your body to break down fat) and lots of fruit and veggies. Try to snack on fruit and vegetables as they are low in calories and fat but will help to fill you up and are really good for you. If you are extra hungry between meals have some veggies dipped into some low fat hummus or tomato salsa dip. Also make sure that you drink plenty of water- aim for 2-3 litres per day.
Exercise is also really important. This will increase your metabolism (so will help you to lose weight faster) but will also tone your body, making you feel great. Aim for about 30 mins every other day at first then increase this as you get stronger and fitter. Something like jogging is great as already suggeted, also swimming is great and even just walking everywhere will help. Try to include a range of exercise so that you don't get bored. Also aim to include some resistance work (push ups, sit ups, weight, pilates, yoga or whatever) about twice a week.
Note- if you are exercising this may mean that you gain some muscle (don't worry this won't make you bulky unless you take lots of testosterone) it will increase your metabolism (each pound of muscle burns 50 calories more per day) so will help you to lose fat. Even if you aren't losing lots of weight, I you will be getting smaller as you will be losing fat.
Good luck- you can do it!