Jacksonville's international airport is the closest large airport to the venue. To reach St. Augustine it does require further ground travel so we recommend making the proper transportation reservations ahead of time. There are also Uber and ride share options available from the airport terminal.
Orlando's international airport is a longer drive to the wedding venue in St. Augustine, however it is still an option for any guests choosing to visit the theme parks the days before or after the ceremony (sans Erin and Phil)