So I'm a personal trainer, who lost 10stone about 8years ago and has mostly kept it off.
Ok so if I were you, and I have been plus a lot more weight, I would aim for 1lb/week weight-loss, which is a 500Calorie a day deficit.
Prioritise protein in your meals, if you eat meat then that would be your meats, if you're vegetarian (like me) then beans, pulses, tofu and meat substitutes.
Meal prep as much as possible, batch cook and freeze meals that you've calorie counted. I have a freezer full of home made curries, stews, home made pasta sauces and cottage pie.
Create a plan for a weeks meals, and do your best to stick to it. Don't buy the foods that you'll binge on, easier said than done when you have children, I know.
If you like to eat a lot of food then it's still possible to volume eat. I make huge bowls of salad, using things like rice and beans, so big that I can't eat them in one sitting, but they have less than 500 Calories for the whole bowl.
Activity wise, the recommended minimum is 150minutes of intentional, moderate exercise or 75minutes intense exercise a week, spread over 5 days. This doesn't need to be all in one go, you could go for a brisk 15 minute walk in the morning and another in the evening. And intensity is relative, what would be a brisk walk for you might seem like a stroll for someone else, you just want to get your heart rate up.
I would also recommend incorporating some sort of resistance training, this can be bodyweight or with actual weights. There are lots of great videos and workouts available on the Internet. Recommended minimum is 30min twice a week. Resistance training will not only help you look better as the weight comes off, but will also help reduce the risk of osteoporosis.
No matter what with the exercise, find something you enjoy, it's then more likely you'll stick with it.
Finally, don't focus too much on the number on the scale. I'm 78kg, 4'11" and a size 10-12. BMi has me as obese, but in reality I lift heavy weights and have a much higher than average muscle mass. I'm also a marathon runner, not a fast marathon runner, but a marathon runner none the less.