Hey Islem_h! Your project really sound exciting. Cross validation operator is a really powerful tool! It can be used to estimate the statistical performance of a learning model. Below I have set up a project with cross validation in place which you can take a look at it.
I have uploaded the image to my drive because I'm facing an error while uploading it here. Probably because I just joined. drive(dot)google(dot)com/open?id=1B11WunE16eQxLWD_6CAbqG_9F1jE0I0w
Hope this help with what you want to achieve.