When exactly should I pay the tuition?

I am an international student and this is my first experience with american college. And because of that this may be a stupid question to a number of people…but when exactly should I pay the tuition?
UT website says that I need to register first, but when exactly do students register? maybe after orientation?

You will register for classes at Orientation, as well as upgrade your EID, your student ID, giving you more online access to the Registrar’s Office and what you owe. Tuition payment for Fall semester this year is by 10 Aug.