You should be familiar with the facilities of the system, logging on to TSO and using ISPF. A knowledge of resources like data sets, DASD volumes, and programs is required to get the most benefit from the course. This knowledge might be obtained by attending Fundamental System Skills in z/OS (ES10), or consider taking Basics of z/OS RACF Administration (ES19) instead of this course. ES19 spends the first day covering these prerequisites and provides a more basic understanding of RACF than Effective RACF Administration (BE87).
You might also find it beneficial to attend z/OS Security Server RACF, Implementation and Customization (SZ81) to learn the implementation and customization of the z/OS security server RACF.