wp_enqueue_scripts

<?php
/**
 * Proper way to enqueue scripts and styles
 */
function wpdocs_theme_name_scripts() {
    wp_enqueue_style( 'style-name', get_stylesheet_uri() ); // style.css
    wp_enqueue_style( 'slider', get_template_directory_uri() . '/css/slider.css',false,'1.1','all');

    wp_enqueue_script( 'script-name', 'https://cdnjs.cloudflare.com/ajax/libs/fuelux/3.15.10/js/fuelux.min.js', array(), '1.0.0', false ); // If you used true then it load in_footer, Default: False
    wp_enqueue_script('oxfam_js_cookie', 'https://cdnjs.cloudflare.com/ajax/libs/js-cookie/2.1.0/js.cookie.min.js', array(), null, true); // Remove version variable by using null
}

add_action( 'wp_enqueue_scripts', 'wpdocs_theme_name_scripts' );

// It just works on template-name.php
wp_register_style( $handle, get_stylesheet_directory_uri().'/relative/path/to/stylesheet.css', array(), '', true );
if ( is_page_template( 'template-name.php' ) ) {
    wp_enqueue_style( $handle );
}

// Depedency of script. If 'jquery' and 'jquery-ui' not load then it will not load
function myscripts() {
    //get some external script that is needed for this script
    wp_enqueue_script('jquery-ui', 'http://ajax.googleapis.com/ajax/libs/jqueryui/1.9.1/jquery-ui.min.js');
    $script = get_template_directory_uri() . '/library/myscript.js';
    wp_register_script('myfirstscript',
                        $script,
                        array ('jquery', 'jquery-ui'),
                        false, false);
    //always enqueue the script after registering or nothing will happen
    wp_enqueue_script('fullpage-slimscroll');

}
add_action("wp_enqueue_scripts", "myscripts");

?>