Here is what has worked for me and is accepted approach of weight loss.
1. Figure out your base caloric needs.http://www.bmi-calculator.net/bmr-calculator/
2. Figure out what your needs are for your base + activity level.http://www.bmi-calculator.net/bmr-calculator/harris-benedict-equation/
3. Ensure you are eating under that total daily. Start by cutting it by 500 calories and see how that works. There is variation in everyone so you might want to move that number up or down depending on your results.
The big thing to remember is that it takes time to lose the weight and it honestly seems like it takes forever. You will go through periods where you don't feel like you are making any progress and other times when it seems to be great. Avoid weighing in more than once a week and don't let bad numbers on any given week get you down.
I dropped from 202 lb and 22% body fat to 172 and 14% but it took 9 months and there were certainly times when it was I felt like a stalled but in the end I got there.
I did photos at the start of each month and found that helped because day to day I didn't see the slow changes in my body but when I looked over months It was clearly there. Photo of results posted so you know I am not blowing smoke.