You can have two free tickets at any given time, plus as many purchased tickets as you like.
Every six hours, you are given a FREE ticket for Show Your Style. The maximum free tickets you can have is two, but if you purchase additional tickets, those are counted separately.
When you make your submission to Show Your Style, the game will use your free tickets first. It will not deduct a ticket you have paid for, unless you have used your two free tickets already.