Woocommerce redirection if no previous orders

by

Since you are looking for a redirect after 5 seconds so for this you need to use javascript timeout. You can enqueue script as per standards. Adding this script inside the condition of no orders will do the task.

jQuery(document).ready(function ($) {
    window.setTimeout(function () {
        location.href = "REDIRECT URL HERE";
    }, 5000);
});