Is 189 heart rate to high for a 22 year old during exercise?

A general rule of thumb (!!!) for the safe heart rate is 220 minus your age (e.g. 220-24=194). You're well within that heart rate. If you feel fine at that heart range, it's safe. Your particular heart rate is within the cardio range, which means your stamina will improve. For fat burning, a lower heart rate is better.