When it comes to server operations, Red Hat Enterprise Linux is one of the most important Linux distributions. If you're looking to administrate serious workloads, Red Hat is an excellent place to start.
Red Hat Enterprise Linux 9 (RHEL 9) is the distribution of choice for many critical production deployments. This course, RHEL 9 System Administration, will introduce you to the basics of Linux administration for RHEL 9 systems. You'll learn how to access and move around in an RHEL system, how to take advantage of the many tools available within the RHEL shell environment, and how to securely administrate systems with multiple users and groups. When you're done with this course, you'll be comfortable performing many basic Linux administration operations in RHEL 9.
Homepage:

https://www.pluralsight.com/courses/rhel-9-system-administration