If you have some time and an Abap editor available, these articles can get you started on Object Oriented programming. The examples are all about local class definitions and using globally defined (standard SAP) class definitions, where the simplest form should be effortless to follow.
Get started - by examples.
Imagine a world, where no
FORM routine is needed, ever again. How do you capture the bit of logic you would have captured in a form routine ? Use a method. This simple example shows what you need to define a class
LCL_CONTROLLER which controls whatever your report should be doing.