How to lose weight.

https://www.youtube.com/watch?v=x0LUMkXF-Fs

this is the one which I do

dont be too hard on yourself, you will improve, you will get better

 

Daiki-san I'm not sure, but I think doing ab workouts will make your stomach look bigger short term, because they don't burn as much fat as they do build muscle. You are jogging so soon you'll see a difference.
I do hundreds, knee to elbow sit ups, reverse crunches, sitting twists, planks.
Of course swimming is the best ab workout you can do, so if you have access swim!!
It burns calories and works your abs at the same time.
I would say a good start is to eat first thing when you wake up in the morning and don't eat four hours before bed. Snack throughout the day instead of eating three big meals, spread out what you would normally eat.
Also white and green teas are supposed to be good for the metabolism.
More meat and veggies, less grains, sugar, dairy. You get the jist. You can find a lot of stuff online.

 

Try a combo of cardio workout and muscle workout. Having a good and healthy diet is also very important! I'm on the same train as you Daiki-san!