High-performance computing (HPC) clusters are used for large-scale data processing and data analysis, fine-grained parallel calculations and simulations of ever increasing fidelity. This course is meant to introduce learners to the core principles to use the HPC clusters HEMERA at HZDR, how to connect to the cluster, how to dispatch jobs and retrieve their results, and how to program applications that can harness the full power of this machinery. This is a one-and-a-half-day workshop organized jointly by the HZDR units FWCI-H and CASUS Scientific Computing Core.