These pre-exercises are designed to prepare you for using C++ and ROOT, in a very specific context: editing and running much of the pre-existing code used to access some of the older open data files. This is not a full introduction to either C++ or ROOT, however we do take time to explain some key concepts that will help you feel more comfortably working with the open data codebase.
You should definitely take time to go through either this exercise before participating in the workshop.
If you run into problems with any of these steps, please reach out to the organizers through the dedicated Mattermost channel.