I accidentally closed the confirmation page after I turned in my UC application; I managed to print out the receipt, but was not able to scroll down to read the rest of the page before it closed. Did I miss anything important on that page?
No, it’s just a receipt.
the only thing you might want from it is there’s an application number they give you which you can use to create a login at at least one of the schools (UCSD) until they send you school-specific portal info. But they probably sent you an email also, right? If so, that would have the same info in it as the page you closed so don’t worry! And what you see when you create an account and log in at UCSD right now is just that Fall 2017 applicants should come back and look in January!