i need help

I might just be stupid, but I defeated the girl at the Academy and I’ve been told to continue, but I have zero clue how to get to the area where I assume I need to go to continue shown in photo circled in red

I might just be stupid, but I defeated the girl at the Academy and I’ve been told to continue, but I have zero clue how to get to the area where I assume I need to go to continue shown in photo circled in red