In my admin page for a course registration system, administrators can create courses with attributes like city, school, and course name. Admins also need to manage cities and schools by creating or deleting them. Currently, there's a 'Courses' section on the main page, where admins can view and edit courses and create new ones.
Is it recommended to include a combobox for selecting cities and schools for course creation and management, or should I create separate pages for these tasks? If separate pages are the way to go, what's the best way to navigate to them from the main page? I'm concerned that having a menu like 'Courses,' 'Cities,' and 'Schools,' especially a page just for creating/deleting cities, might seem unusual.
The form

ComboBox with select / create / delete
