Good for you. Changing your body composition takes time and perseverance but it is amazing what the body is capable of.
You will have to change your eating and start exercising. I would caution you to start with small steps,turn them permanent habits and then add another aspect to your plan.
There is a wealth of great info available, but please be realistic..some rough guidelines...losing more than 2lbs a week is water (2lbs per week is on the high side if you are talking true body fat). Building muscle...for a woman you are looking at about 1 lb/month, a little more in the beginning but that is a realistic number.
Getting to a "fitness model" level is around 18% bodyfat. That is not easy to do and unlikely to maintain. At 18% and below say good bye to your breasts, hello to weird prominent glands that poke through your skin...ones you never knew you had, the ones they airbrush out of the ads, the ones you wish you have never seen!
Not to mention the eating regime is extremely strict.
I am 5'9", 21% body fat right now. I look lean even now. I mention this as a positive, unless you are interesting in competing, you may not need to reach such a low BF% to achieve your desired look/fitness.
Be good to your body and make healthy changes...don't buy into anything that sounds quick and easy....and if it comes in a capsule, save your money!
Take care, Mythos