The goal is glucose / insulin control. Forget calories. Insulin is a fat storage hormone. Go keto or carnivore. This comes from someone who has yoyoed a fuckton with calorie counting. You never get over the carb / sugar addiction, especially with "everything in moderation". Therefore, you fall back into old habits and the weight comes back. Calories in / Calories out does not account for hormones. You'll get calorie reduction with very low carb / no carb anyway due to high satiety.
You don't have to stress about working out. Movement is important, but you don't have to get a gym membership or start taking up running. Walking as often as are able is good enough. Lifelong dietary change is 95% of the work.
Cut out sugar consumption entirely. Some will sneak in if you have to eat at American resturants. Although I do have some sweeteners, there are only some that don't spike blood sugar (and insulin) for me particuarly. (Stevia, monkfruit, erithritol) But I try to avoid the sweet profile as much as possible. Yes, this also means fruit. Fruit is full of sugar. Sweet tasting items release insulin.
Don't consume any grains or starches. (wheat, most flours, potatoes, starchy veg).
Avoid / eliminate processed oils (seed oils, canola oil, etc). high quality olive or avacado oil is okay, but just plain butter is best.
Up your protien intake, probably by a lot. The amount you should eat will differ greatly, but most people aren't getting enough protein. Beef is the most nutrient dense food you can eat.
Intermittent fasting, or going to one meal a day, alternate day fasting or occasional 24-36 hour fasts.
Up your salt intake by A LOT. I cannot stress this enough. You'll be losing water, and peeing out sodium. You'll have to salt your food and probably put a bit of salt in your water. Most electrolyte drinks / powders contain sweeteners.
Going this route is a lot easier than it sounds. It's sustainable and doable in the long-term.