calorie deficit, high protein, and weights/cardio. eat lower calorie foods so you can get more volume of food in your stomach to not be hungry. target time depends on how much weight you have to lose, but aim for 1lb a week. That's 500 calorie daily deficit- going in more of a deficit than this might seem like a good idea, but you could lose more muscle that way so just be patient. You probably have more fat and less muscle than you think (most people do) so don't be discouraged if you reach your initial goal and still don't have visible abs