Syntax Validator (Error)

Syntax Validator (Error)

Good night people!
I have a problem with not knowing jQuery very well.
I installed "Linter-eslint", "Linter-jshint" among other plugins in my Sublime Text 3 to help me find the error, but I did not succeed. I tried using up the Esprima ( http://esprima.org/demo/validate.html ).

My code is a form that goes through 4 steps until it is submitted.
Can someone help me see where the error of my code is?

And what tip can you give me to debug and debug my future codes to avoid such questions in the forum? What can I do, what techniques and tools to use?
Thanks for listening!

MY CODE: