when i was teenager, i did some strict cardio (whole body + face, like jumping jack, squad, lunges, bent over, side lunges, wide row, etc, and for face exercises i usually use the japanese one), i didn't have any channel rec, cause most of videos i use is in bahasa indonesia, but there's so many in yt!
i did the cardio everyday (minimum 1 hours, max 3 hours), i don't eat carbo, or high salt/msg food (only healthy, fibrous, & high protein food) and i also did fasting (3-4x per weeks), like every monday, wednesday, friday, sunday (alternately) like today fasting, then tomorrow i ain't do fasting,
and from 50 i lose 10kg in 3 months.
Keep doing it until you get the ideal one, the result is my body has a pack, but if you want a more defined body, like maybe a booty one, better hit the gym