How to include smoothState.js or any JS library in wordpress theme efficiently

Question

me and a friend web developer tried so many solutions before bothering you here. We humbly ask your help, We also saw that Stack overflow is open for help if we put the tag : smoothState.js. we really need your help, here's our problem :

We tried to include the JS library (or jquery plugin i should say ) in my wordpress theme https://github.com/miguel-perez/smoothState.js#intro

and we followed this article instructions to achieve that : https://webdesign.tutsplus.com/tutorials/how-to-integrate-smoothstatejs-into-a-wordpress-theme--cms-26610

So the steps we followed are : 1- create a child theme 2- copy and paste the jquery.smoothState.js from github repository to main theme --- asset --- js [1]: https://i.stack.imgur.com/CfMGS.jpg here's the screenshot : [enter image description here][1]

3- use the wordpress function to enqueue javascript in function.php of the child theme : The code is like that :

wp_register_script( 'scount', get_template_directory_uri() . '/assets/js/jquery.smoothstate.js' );
wp_enqueue_script( 'jquery-smoothstate-js', 'assets/js/jquery.smoothstate.js', array( 'jquery' ), '0.5.2' );
wp_enqueue_script( 'script-js', 'assets/js/script.js', array( 'jquery', 'jquery-smoothstate-js' ), '1.0.0' );

4- create a script.js in the theme folder ---- asset --- js and we putted this code :

<script type='text/javascript' src='wp-includes/js/jquery/jquery.js'></script>
<script type='text/javascript' src='assets/js/smoothstate.js'></script>
<script type='text/javascript' src='assets/js/script.js'></script>

( function( $ ) {

    $( function() { // Ready

        var settings = { 
            anchors: 'a'
        };

        $( '#page' ).smoothState( settings );
    } );

})( jQuery );

then we added the css found in the article in order to add an animation :

.site-content { -webkit-transition: -webkit-transform .28s, opacity .28s;

-ms-transition: -o-transform .28s, opacity .28s;

-o-transition: -o-transform .28s, opacity .28s;

transition: transform .28s, opacity .28s;

}

Please help us ... and if you do, be as clear as possible, we are two beginners and we need clear instructions without confusion. What is wrong with what we did ? We searched the whole internet on how to add JS library in wordpress and that's all we found. Why it is not working ?

Thank you in advance