Is Coenzyme Q10 right for a 24 year old girl?

to tell you the truth, a lot of supplemental stuffs are not FDA approved or thoroughly studied.  you take them with your own risk.  I assume you are a healthy human being, normal kidney, heart, no diabetes, among other things.  assume you dont take any weigh loss products or sinus medications.

Co Q10 may boost your metabolism. you can take it, starting lower dose than recommended from the bottle. when you see no side effects, then you can increase slowly to the recommended dosage.

I hope it helps.
ps. pay attention to your heart rate. and remember to take a lot of fluid.

At your age, supplemental Co-Q10 is not necessary.  You already make all you need.  Levels drop off as you age, and you may benefit from supplements after age 50.  You won't get any benefit from it at your age.