Advice in digitizing guitar gadgets?

Question

Circuit design

It is necessary to qualitatively digitize the guitar lotion. There is a pedal itself, scheme0 , scheme1 , scheme2 , Matlab.
In the end, we need a C ++ method that handles the signal, but first I would like to understand where to start. As I understand it, for a good approximation and the ability to turn the "twist" you need to approximate each specific detail of the circuit. How to approach this task?
Need to feed the input of each part and remove the output? If yes, how to do it? (removing the output of the lotion itself with the help of daw does not cause problems). Or is it enough to emulate all the details (resistors, etc.) using software (what?) And see what happens? And how to use this model from C ++ for sound conversion?
I must say right away that I am not a specialist in circuitry, digital signal processing and data approximation. Therefore, I am considering the possibility of hiring a specialist for money. But for now, I'm trying to figure it out.