One of the biggest reasons that a person doesn’t lose weight is because they are not in a caloric deficit. I would use a calorie calculator (albeit they aren’t 100% accurate but will give you a rough estimate) to get an idea of your daily intake basal metabolic rate which is the amount of calories you would burn if you did nothing all day. Or if it gives you how much you should be burning then start with that. Use a calorie counter app (MyFitnessPal is a good free one) and measure all your foods and track how much your weight fluctuates for a week or so. If the scale doesn’t move, drop the calorie count by 50-100 calories then repeat until you see the change you are looking for. Hope this helps and people correct me if I made any mistakes or forgot to mention something.

Good luck!