It depends on where you ordered your cardarine GW from because each research chemical site has a different dosage.
Cardarine from sarms1.com is dosed at 20mg/ml. 10-20mg/day is a good dosage for males. 0.5mL = 10mg.
I would dose 0.5ml (50 units on the insulin syringe) before breakfast and 30-60 minutes before your workout.