I'm a 40 years man, i quit smoking 12 days ago,what's your recommendations to stay healthy? and what types of periodic examinations should i take?

Smoking cessation: Congratulations on becoming smoke free. Keep up the good work. Staying healthy includes not smoking, eating a balanced diet of protein, fats, and carbs. Regular exercise such as brisk walking or jogging, and a good mental attitude. Please see your doctor to make sure you are healthy enough for the above and visit him/her yearly. Peace and good health.