1. I believe this happens because WordPress processes shortcodes after the page has been rendered when it calls the_content, and echo seems to just render to the top of the page. You can modify the code above to return the string rather than echo the string, which should place it exactly where the shortcode appears in your post/page. Like this:

function HelloWorld() {
    return "<p>Hello World! This is my custom function.</p>";
}

Notice the <p> tag which helps it appear like a paragraph would in your post/page.

2. You need to modify the function and shortcode slightly.

Change the function so it accepts the $atts argument. The $atts argument is an array containing however many attributes that we have chosen to pass to the function via the shortcode in a post/page. In this example we are only passing one attribute (name), so we extract $atts to put the first attribute into a variable called name ($name), whose value equals whatever we specify in the shortcode, unless we don’t specify a value in which case a default name of ‘Nobody’ is used:

function HelloWorld($atts) {
    extract(shortcode_atts(array('name' => 'Nobody',), $atts));
    return "Hello World! My name is $name.";
}

Then change the shortcode in your post/page so it passes a value for the name parameter to the function.

[hello name="perry"]

Someone feel free to correct me if I’m wrong, I’m only a few weeks into PHP and WordPress development

Thanks again

If you want to use a contact form on a self hosted WordPress blog, check out one of the various Contact Form plugins at the WordPress.org Extend page.

1. Following your exact procedures, the “Hello World! This is my custom function.” appears at the top of the post, no matter where in the post I add the shortcode.

2. How do I pass a parameter to the function through the shortcode. e.g. in your example let’s say we want it to say, “”Hello World! My name is xxx.” – How would we implement the name variable into the add_shortcode line of code, and how to add it in the shortcode itself?

Thanks again.

Hopefully this plan will work!