HPC Fundamentals for end-users is an introductory course on how to use Discoverer supercomputer, a EuroHPC petascale system capable of executing more than 4.2 Petaflops Rmax and over 6 petaFLOPS  Rpeak, by users with no prior exposure to supercomputing systems. This is the first training course in a series of two courses for beginner and intermediate HPC users that will allow them to master their skills, knowledge and confidence to work with supercomputing environments. The course will start with introduction to the Discoverer systems and computing architecture including storage subsystem and computer network infrastructure. During the four days training, there would be a number of hands-on exercises so that attendees will gain immediate experience on working in typical user environment by building and running state of the art parallel codes on Discoverer system. Practical sessions will cover examples from different research fields such as Life Sciences, Material Science and Multiphysics simulations. Sofia TechPark will graciously provide Discoverer compute resources for the hands-on sessions. The series of two courses is joint effort by NCSA Bulgaria and PetaSC/Sofia TechPark, BioExcel Centre of Excellence, STFC Daresbury Laboratory.