Start with balanced diet as of your age you shouldn't restrict much on diet but get a balanced diet plan which suits you best, and gradually start with small exercises at home for half hour daily and also try walking, and after sometime you can join gym and never skip any meals or take diet plans that wont suit you, dont be afraid to get fit, but dont go to extremes of it.
Next Steps
Check your FLP(fasting
lipid profile) for cholesterol and TFT(
thyroid function test).
Health Tips
Drink enough water and eat healthy, start with small exercises and gradually impoverise.