I have a new Joomla 3.8 instal and have installed the SJ Joomla 3 template. After installing the template a message now displays in Chrome that says "This page is trying to load scripts from unauthenticated sources."

This error only occurs when the site is opened using HTTPS.

What scripts need to be removed from the template to prevent these errors from occuring?

This usually means that your website is hacked and Google has marked it insecure. Sometimes even when you fix the hack, the error still shows up. There is, however, an option allowing users to bypass this warning and enter the site. Even though it is not advisable to remove Deceptive Site Ahead filter from your browser, you can do that by following these simple steps:

Start Google Chrome.
Click Menu or More icon in the upper-right corner.
Select Settings and Show advanced settings.
Go to Privacy and deselect Protect you and your device from dangerous sites.