A person should always check with their physician before beginning an exercise program. After that many people find walking enjoyable. That's a good question too. For instance some people have difficulty clearing fat from the blood so they have higher levels of triglycerides and alcohol can make this problem worse. For this reason its important to know what your values are.
Smoking is a strong risk factor for heart disease.
Smoking almost doubles the risk of heart disease at any cholesterol level according to the American Heart Association. Those are great questions. A good place to start is to remember that the vast majority of Americans do not exercise regularly so increasing activity is one of the Healthy 2000 goals for all Americans. It is true that different types of exercise do different things but both endurance training and strength training are beneficial. The Amercian College of Sports Medicine recommends both endurance and strength for overall health.