No one is too young for heart disease
The term heart disease just means something wrong with your heart in general, and anyone can have that.
Teens such as you would have a form of heart disease called Congenital Heart Disease which is where you are born with a heart problem.
Sometimes they do not detect these things right away when you are born. Some are not detected until adulthood.
I would not worry about having something wrong with your heart as it only occurs in 10 out of every 1000 births and usually you will have a heart murmur
, which is a certain sound a doctor hears when they listen to your heart. They would tell you if you had one.