src script only works on home page?

First, don’t put script tags directly in template files, enqueue them from your theme/child theme’s functions.php. Second, use the API to output URIs for scripts, don’t hardcode or use relative paths.

function wpdocs_theme_name_scripts() {
    wp_enqueue_script(
        'flexslider',
        get_template_directory_uri() . '/js/jquery.flexslider.js',
        array('jquery'),
        null,
        true
    );
    wp_enqueue_script(
        'fancyselect',
        get_template_directory_uri() . '/js/fancySelect.js',
        array('jquery'),
        null,
        true
    );
    wp_enqueue_script(
        'myscript',
        get_template_directory_uri() . '/js/script.js',
        array('jquery'),
        null,
        true
    );
}
add_action( 'wp_enqueue_scripts', 'wpdocs_theme_name_scripts' );