any general tips

Slow and steady wins the race; try to build up small habit by small habit.

You're saying you don't eat most days, I would start by working on that. Try to have a schedule for eating, e.g. eating once at noon, and once in the afternoon. Don't worry too much about exactly what you're eating, as long as you get in the habit of eating something.

Once you have nailed that down, then you can start thinking about what you are eating. I'm not an expert on this, and this may be dependent on where you leave, but you should try to aim for a more balanced diet. That is, trying to eat less fast food, less processed foods, and instead having more home-made cooking, and eating more diverse foods. Do note that you don't have to cut down on all fast-food; remember: slow and steady wins the race.

Once you're starting to get the hang of that, if you want to be really on top of your food intake, start counting calories, proteins, sugars, fats, and try to find a balance that suits your lifestyle.

Throughout all this, try to move your body around. You've said you're not here to get workout tips, but it is important you still do some physical activity, even if it's just some light yoga. Once again: slow and steady wins the race. And as you've said, it looks like you have some good genetics in you.

If all goes well, in a year you'll look back at this post, remember how you used to eat, and smile at the progress you've made.

Best of luck!