If you are not trying to put on muscle I would not reccomend training, I don't work up a sweat that way and burn off alot of calories and it makes you hungry so you will eat more.
Unironically walking, if you are fat it will not fuck your joints like jogging or walking, walking UP A HILL is advice you will not see about walking too. Walking also burns calories but does not make you hungry.
Then eat foods with few calories, fruits and veggies generally.
Try brushing your teeth through the day or having something minty, you will not want to eat with this mint feeling in your mouth.
Drink water ONLY, everything else has calories.
Learn to cook, fast food is calories galore.