My javascript coding learning stage

i have finished all my html and css project and now i have entered on javascript section, but i am finding it difficult to understand it , i don’t know maybe if i didn’t start from the beginning please someone should tell me,
i am taking to this stage but doesn’t understand anything here;

Palindrome Checker

Return true if the given string is a palindrome. Otherwise, return false .

A palindrome is a word or sentence that’s spelled the same way both forward and backward, ignoring punctuation, case, and spacing.

Note: You’ll need to remove all non-alphanumeric characters (punctuation, spaces and symbols) and turn everything into the same case (lower or upper case) in order to check for palindromes.

We’ll pass strings with varying formats, such as racecar , RaceCar , and race CAR among others.

We’ll also pass strings with special symbols, such as 2A3*3a2 , 2A3 3a2 , and 2_A3*3#A2 .

Have you done any of the JavaScript challenges?

There are 9 JavaScript sections before the projects.
If you haven’t done any of those 9 sections, you will need to start from the beginning here

oh thank you jwilkins.oboe !
you are indeed a savior, i was in the wrong direction before but the link has directed me to the right part,
i appreciate for your quick reply