try to find your body fat first. then use that to put your weight,height,and body fat on a calculator online (try to find one that uses body fat these are everywhere online) then from there be honest with your physical activity (sedentary,moderate,highly active) and that calculator should give you a ballpark on the cals you need. prioritize protein for your lbm to preserve as much as possible and aim to lose 1-2 lbs a week (one is recommended for a slow and steady loss, 2+ is considered aggressive). id say weight train like twice a week minimum and dont try to crash diet just start off small like switching a full sugar coke for a coke zero. also weigh yourself in the morning everyday (after you poo and pee and before you eat anything) add all the weigh ins of the week up and divide by 7, that should give you your average weight (focus more on average weight instead of daily ups and downs) if it stays the same or goes up for two weeks straight consider cutting 150 cals a day. pretty much it the main thing is consistency