Hope you find the answer

You can simply trash it from the edit of the post.

If you want to delete the whole post you can do that in the WordPress editor.
If you only want to delete the content you mark it and delete it.

New to me

Sorry, I don't know that convertkit. What is it?

I see these instructions plus you need a paid service to make this work

https://wordpress.org/plugins/convertkit/

Description

ConvertKit makes it easy to capture more leads and sell more products by easily
embedding email capture forms anywhere. This plugin makes it a little bit easier for those of us using WordPress
blogs, by automatically appending a lead capture form to any post or page.

If you choose a default form on the settings page, that form will be embedded at the bottom of every post or page
(in single view only) across your site. If you wish to turn off form embedding or select a different form for
an individual post or page, you can do so within the ConvertKit meta box on the editing form.

Finally, you can insert the default form into the middle of post or page content by using the [convertkit] shortcode.

Full plugin documentation is located here
Screenshots
FAQ

Installation Instructions

Upload wp-convertkit to the /wp-content/plugins/ directory
Activate the plugin through the ‘Plugins’ menu in WordPress
Visit the settings page by clicking on the link under the plugin’s name
Enter your ConvertKit API key, which you can find here, and save the settings
Select your default form and save the settings
If you wish, choose particular forms for each post or page by visiting the edit screen and choosing the correct form


Installation Instructions
Does this plugin require a paid service?

Yes, for it to work you must first have an account on ConvertKit.com

Etsy is an affiliate program like Amazon, you can sell Etsy products by using affiliate links on your site.

Unfamiliar with name

Sorry..I never know that and i can’t find for your right answer..

Either one

I use autoresponse, and I like it.

Either Aweber or GetResponse. I am currently using Awaber but thinking to switch GetResponse to see what it is out there. I heard Mail Chimp is not Affiliate friendly, so I would not recommend it.

After you add the link to your post are you remembering to update your page?

For HTML code
Just copy the code and go to your post editor in Wordpress and in there you need to toogle to 'text' tab (not visual tab) as you are pasting html code here.
Find the place where you want in to be displayed and paste the code there.

LINK
If it is a normal link, just get the word you need to hyperlink as per normal (no need to toggle to text tab) and create the link.