Write down what you eat for a while and its calories. Weigh yourself daily as well and write that down too. If after a week your weight went up: Your calories are above your TDEE. If it went down: Your calories are under your TDEE.
And that's basically it, once you know what your TDEE is, eat under it to create a caloric deficit and you will lose weight. Even if you don't exercise at all and just sit at home.
Sure exercise will help putting your caloric deficit lower by burning some, but in the end it's always calories vs TDEE. Understanding that makes it very easy to go in either direction (gain weight vs lose weight), no matter what your metabolism is
(The easy solution is of course to just eat less, like skipping a meal or reducing the amount. Since your average daily food is already what dictates your current weight, reducing it means you will lose weight)