Creating a calorie deficit will result in weight loss. That's for sure. It's not automatic though and you must give it some time. Having made the decision to lose the weight, once and for all, I'm sure you're super anxious to get rid of it. But we must remember, it didn't come on in a short time and it won't come off in a short time. Weight loss is not an immediate gratification type thing. But hang tight - it IS extremely rewarding as you lose the weight and you are feeling better. As you become more active, more productive, more energetic and more fit. As your clothing size plummets. It's one of the most exciting things you can imagine.
I would definitely start out at a higher calorie count, given your current weight. 1800 cals will most likely provide you with a calorie deficit. There is definitely trial and error involved in finding the right numbers for yourself. Fitday.com is a website that can help you track calories.
As far as exercise, do as much as you can and before you know it, you will be able to increase it.
As far as your food. You MUST, absolutely MUST find a plan that you can STICK with. Cause if you don't stick with this, then you won't be able to lose all the weight - permenantly. Therefore it is important to find something that you can *do* longterm. I like to eat small, frequent meals and snacks so that I don't get hungry. Fiber and protein are weight loss and nutritional powerhouses. I would try to incorporate them into each and every meal. Egg white omlettes, no fat/no sugar yogurt, cottage cheese, chicken and turkey breast, soy products, tuna and other fish. Then there's the fiber - high fiber cereals, veggies - such as carrots, cauliflower, various squashes, broccoli, string beans, etc. And fruits. Berries are fabulous, pears, apples, peaches, etc.
Also very important to have a plan in place. Eating healthy does not happen by chance and therefore must be planned out in ADVANCE. Know what you will be eating ahead of time. Keep your home fully stocked with healthy foods. Get rid of the junk. Set yourself up for success!
Take a look around 3FC. There's lots to learn and lots of info.
Good luck to you as you embark on this very, very rewarding and extremely worthwhile journey.