When taking creatine for exercise it's best to take the creatine just before you begin your workout.
It can take up to 4 days of taking the creatine to see and feel the results of taking creatine but if you continue to take it daily you'll feel the results.
You can take creatine after your workout or long before your workout but you'll do better and the creatine will work much better if you take it within 10 to 30 minutes before you begin your workout.