Explore GPU simulations and the AsterX code in this comprehensive tutorial presented at the 2023 North American Einstein Toolkit School and Workshop. Learn from experts Jay Kalinani, Lorenzo Ennoggi, and Liwei Ji as they delve into advanced computational techniques for relativistic astrophysics. Gain insights into leveraging GPU technology for high-performance simulations and understand the intricacies of the AsterX code, a powerful tool for numerical relativity. This 1-hour and 14-minute session, hosted by the Center For Computational Relativity and Gravitation at the Rochester Institute of Technology, offers valuable knowledge for researchers and students in the field of computational astrophysics and gravitational wave science.