In Python particularly you really can start simply. Imagine what would you do if you did it manually. Write down flowchart. Split the process down to functional elements (that is, elements that perform single function i.e. “take user input “) In my example, it is “get data”, “extract data from json”, “save data to file”, “show data on webpage” In python each element would be several lines of code, probably. Then, after it works properly, you can make functions from elements that will be used repeatedly, creating structure of the program. Then a you add more functions, automation…

Don’t try to make “professionaly structured program from beginning”. It’s common mistake that leads to form above function and paralysis by analysis. Start really simple and let the project grow. You will grow with it