See output of function — newbee question

Hello:

I have a function that was written with the help of several people. I placed the function in my child theme function.php file. Although the function appears to work I have some concerns.

What I would like to do then is learn how I can capture each step (functions within) an add_action function and display its content…

Is it possible to directly echo the steps the function is performing to a wp post or page as they occur so I can validate each step.

I know I may not have said this quite correctly but I hope someone gets the idea of what I need to do and presents a solution developers use to determine each functions output as it iterates through an add_action hook function.