You have never had hands on experience with Business Rule Framework? Not to worry, you can learn by playing the game Rock, Paper, Scissors. All you need is access to a SAP ECC or S/4 HANA system where Business Rule Framework activated and you have full authorisation associated to the transaction code BRF+.
Then simply sign up to receive daily emails that include all the instructions. You get acquainted with all the core functionality and terminology while you are building the game.
Good luck,
Isard Haasakker.