Weight loss logistically is very simple. Eat less calories than you burn and you will lose weight.
Google tdee calculator and use that to determine your tdee ( the total calories your body needs in a day to maintain its weight depending in weight, height, gender, age and activity level.)
All you then need to do is eat less calories than your tdee a day to lose weight. If you eat about 500 calories less a day you should lose approximately 1lb per week ( as 1lb of fat is equal to approx 3500 calories, 3500/7 days = 500 calories).
Log your calorie intake using myfitnesspal.co.uk , be sure to be as accurate when logging calories as possible. And don't forget to include things like sauces and cooking oil. When trying to lose weight it is better to overestimate than underestimate your calories.
It's normal for your weight to fluctuate a few pounds or so, don't worry about this it is mostly water retention and the weight of stuff in your digestive system. If you don't see any weight coming off after 4 weeks however then either your tdee is lower than estimated or you're counting your calories inaccurately, so lower your calories some more or be more careful with logging calories.
Try to eat a balanced diet, by keeping your nutrition on point you're less likely to crave big junk meals or binge. But on the same point, allow yourself treats within your calorific goals. You'll be more likely to give up and lose motivation if you're miserable on the food you're eating.
If you reach a plateau in weight loss it'll likely be because your tdee is now lower and your deficit is no longer big enough to keep losing at your previous steady rate. So recalculate your tdee and eat below it again.
Once you have lost the desired amount of weight you will need to recalculate yor tdee and eat that amount of calories on average per day and you will maintain your weight.
Don't expect weight loss to happen overnight, it's a long process and a lifestyle change.