If you have no experience in programming, it is recommended that you start learning the basic syntax of python, perhaps by completing the free intro python course at Codecademy: https://www.codecademy.com/learn/learn-python as well as working through the exercises in Python for Astronomers: https://prappleizer.github.io/ .
You might also start reading intro college-level books on Astronomy, such as the OpenStax textbook: https://openstax.org/details/books/astronomy/ , especially the sections on observational astronomy, stellar evolution, and supernovae. A more detailed list of optional preparatory reading for your specific program will be sent to you along with the Participants’ Handbook.