I really want a semi-six pack but I need help?

I am a 16 year old male and right now I have overall not much muscle anywhere, most of my body is fat. but i look like I would have a healthy body because when I have a shirt on I actually look fairly skinny but theres one problem to that...I don't have a healthy body under that shirt haha. Some of my friends that are girls started poking my belly and saying "are you squishy or hard?" and they found out I was squishy it sucked!!! Humiliated I came here to ask you guys how I can at least get a thin body with decently muscular arms and not a full blown six pack on my torso just a semi-six pack please D: thanks! Please don't just say: eat good and do cardio :( get in detail pleaseee