Is it okay for my heart if I drink a couple cups of coffee in the morning before I do cardio?

Probably. Caffeine is a stimulant. It has been shown to enhance athletic performance in many studies. But you have to be careful, especially if you have never used it before. Some studies have shown decreases in heart blood flow, which certainly would be detrimental of you have underlying heart disease, are excessively overweight, or have high blood pressure. Trial small amount 2 c if can handle ok.