QUestion about mapping fields from form

Your software
My Mautic version is: 2.6
My PHP version is:

Your problem
My problem is:
I wonder how to map fields from the campaign form to the segment?
I have name, email and one field that is dropdown selection
Based upon what user selects in the form from dropdown form, they will get a different email…
I am setting up 1 mautic for several sites…

still being confused after studying videos, tutorials etc…

These errors are showing in the log:

Steps I have tried to fix the problem: