Beginning to consider material for an upcoming "choosing a subject" photography class.
Selecting what to photograph is a personal decision dependent on so many varied individual experiences, interests and skills.
To organize a generic overview for a diverse collection of photographers would to be difficult - if not impossible.
As a way of a solution, consider driving from Indianapolis, to Chicago. The most direct route would be Interstate 65. While not as direct, but more varied and interesting would be selecting alternative "blue highways" connecting the two cities. In either case, you go from Indy and arrive in Chicago.
Here the generic how to choose a subject - Interstate 65 - and the individualized - blue highways - both get you from start to finish.
When choosing a subject, it is wise to have a goal - finish - along with an understanding of your individual experiences, interests and skills - blue highways.
Will continue to refine and develop this further.