If you're not even a tad bit muscular, why not focus on that first? 8kg is a lot of weight, man, and when you lose it you're going to look like sh**.
Just start lifting on a program-- 5/3/1 is very popular here, and you should perhaps look into that.
Drink a lot of water--don't get your calories from liquids unless it's a whey shake after workout.
Make smart food choices. Veggies, meat, low fat dairy, etc.
It's going to take time, man. No reason to f*** your body up by trying to do something in a day that takes years. Enjoy the ride.