It is really important to have excellent file management at all times but it is especially important when writing programs.
The most important thing to do is to ensure that the files are named correctly and stored in logical locations.
Make sure that your files have .py on the end to indicate that they are Python files.
Give the filename a description of the program. For example quiz.py for a quiz program.
When you make new versions save different copies of the program e.g. quiz_v2.py or use version control software.
Look at the GitHub guide on version control for detail on how to set up GitHub.