How to quickly start developing GUI, functions have been implemented

Hi,all.I have been implementing some funtions with jupyternote book which manages Slicer Application as a kernal.For me,I am able to do some things with python code.However I have never touched the GUI part,I can define a function to finish what I want,but for some users,I just can’t give them the notebook and let them change the parameters to produce the results.
I have been looking through some tutorials online like these:
1642058730(1)
1642058741(1)
Also,I have been playing with Extension Wizard recently, but since vtk,ctk,qt and slicer come together,I got confused and dont know how to change the template and wigets:
image
Are there some tutorials or videos which can guide me from the scratch,or say,for example,
Just create a simple function with one APPLY button to caculate the maximum value of the volume while input params is just a volume and outpararms is just a number, something like this ,not too many wigets and logics.