How do I Redirect to a 'Thank-You' page after form submission?

Question

I have absolutely no idea how to add a 'thank you page' submission to my clients website. I am not experienced in coding, only UI etc.

Here is a [link][1] to site in question.

( EDIT ) Let me elaborate. I am using Blocs (bootstrap wysiwyg app) and there is a form submit. I now need to add a 'thank-you' page redirect for google analytics purposes. The code below is what I believe will be able to help:

$(function()

{ var successMsg = "Your message has been sent."; // Message shown on success. var failMsg = "Sorry it seems that our mail server is not responding, Sorry for the inconvenience!"; // Message shown on fail.

$("input,textarea").jqBootstrapValidation(
{
    preventSubmit: true,
    submitSuccess: function($form, event)
    {
        if(!$form.attr('action')) // Check form doesnt have action attribute
        {
            event.preventDefault(); // prevent default submit behaviour

            var processorFile = "./includes/"+$form.attr('id')+".php";
            var formData = {};

            $form.find("input, textarea, option:selected").each(function(e) // Loop over form objects build data object
            {       
                var fieldData =  $(this).val();
                var fieldID =  $(this).attr('id');

                if($(this).is(':checkbox')) // Handle Checkboxes
                {
                    fieldData = $(this).is(":checked");
                }
                else if($(this).is(':radio')) // Handle Radios
                {
                    fieldData = $(this).val()+' = '+$(this).is(":checked");
                }
                else if($(this).is('option:selected')) // Handle Option Selects
                {
                    fieldID = $(this).parent().attr('id');
                }

                formData[fieldID] = fieldData;      
            });

Answer 1

First, submit the form and then catch the post. Handle the form and redirect.

<?php
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
    // Handle your form

    // redirect
    header("Location: thank-you.php");
    exit;
}
?>
<form metod="POST" action="<?= $_SERVER['REQUEST_URI']; ?>">
    <button type="submit">Send</button>
</form>