Try to get a group of friends together to go walking or swimming.  Having a regular exercise routine makes you more likely to exercise regularly.  Start slow.

When changing your diet the most important thing is to learn.  Learning why certain foods are unhealthy any be enough to discourage you from indulging in them.  Elevated cholesterol levels can also be influenced by diet and exercise.  Ask your doctor what you can do without medication to help lower your cholesterol on your own.  While medication is important for some, for others a simple change in diet will do the trick.