Will drinking coffee, not exercising, and just generally not taking care of your heart permanently damage it?

No and yes: Coffee is not known to cause heart disease although large amounts can cause arrhytmias due to heart stimulation. Not exercising and eating junk can definitely affect your heart and if your arteries get clogged it can lead to permanent damage, heavy use of alcohol and other drugs can hurt your heart as well.

Exercise: Generally not taking care of your heart and body generally don't bode we'll for long healthy living. Damage depends on what not taking care things are going on.

Depends: Generally, the lifestyle you describe is not suitable for healthy living. Increasing pressure on the heart through lack of exercise or using stimulant to increase blood pressure are not recommended for a healthy heart. If you are trying to prevent heart damage, live a healthier lifestyle.