In WordPress, instead of simply adding these to the header, you should use a method called enqueueing which is a standardized way of handling your assets with the added bonus of managing dependencies. Find out how to do it below using wp_enqueue_scripts.
<?php
add_action( 'wp_enqueue_scripts', 'theme_enqueue_styles' );
function theme_enqueue_styles() {
wp_enqueue_style( 'parent-style', get_template_directory_uri() . '/style.css' );
wp_enqueue_style( 'owl-style', get_stylesheet_directory_uri() . '/assets/css/owl.carousel.min.css');
wp_enqueue_style( 'owl-default-style', get_stylesheet_directory_uri() . '/assets/css/owl.theme.default.min.css');
//wp_enqueue_script( 'owl-carousel', get_stylesheet_directory_uri() . '/assets/js/owl.carousel.min.js', array(), '1.0.0', true);
}
To load scripts in footer use wp_footer.
function add_this_script_footer() {
wp_enqueue_script( 'owl.carousel-js', get_stylesheet_directory_uri() . '/assets/js/owl.carousel.min.js');
wp_enqueue_script( 'scripts_js', get_stylesheet_directory_uri() . '/assets/js/scripts.js');
}
add_action('wp_footer', 'add_this_script_footer');