To unlock the Ready To Kompete trophy in Mortal Kombat 11, you will need to complete all of the game's advanced tutorials.
Main Menu > Learn > Tutorial > Advanced Tutorial
There are 19 tutorials within the Advanced section that are split across three categories: Advanced Offense, Advanced Defense and Frame Data.
Finish all 19 tutorials and the trophy will unlock. If you are struggling with any of the tutorials, you can use the Touchpad to be shown the button inputs required.