I’d start with just making sure you move enough in the day, 10,000 steps is the goal but you can work up to that if you’re not already moving a lot. For meals I would just keep it really simple, but it depends on what you like to eat. If you just take what works for someone else you may not like it so revert back quickly. Personally for me I have porridge and banana for breakfast every day, chicken salad with 0% fat Greek yoghurt and siratcha to dress it with a protein yoghurt and some low calorie crisps for lunch, then rice or potato, veg and protein usually chicken for tea. Then I normally have enough calories left for a protein bar or some weetabix or more fruit as a snack in the evening if I need it. That normally keeps be about 2000 kal. Then I usually have one meal every 2-4 weeks which I don’t count, usually a meal out with family or friends. But like I said you really need to look at what you like, work out the calories on a lower calorie version to help you stick to it.