When you sit down at your computer and do a Google search, you're almost instantly presented with a list of results from all over the web. Google get these results by sends bots to discover new and updated pages to be added to the Google index - this is the process known as 'crawling'.
We have a feature on our Business and above plans that allow you to make your courses hidden, meaning they do not show as course cards on your site landing page and won't be indexed by Google. You can learn more about hidden and private courses here. If this is what you would like to do, it's important that you set the course to hidden prior to publishing it and make sure it remains a hidden course.
If you publish a course prior to making it hidden, Google will have likely already crawled it for indexing. Even if you make the course hidden after publishing it, there could be some time between republishing your course as hidden and when Google recrawls your site to find out that you have actually hidden the course. This means Google will be indexing your courses when you don't it want to.
In this instance, you can ask Google to recrawl your site. This is the best way to have Google reflect your recent site changes.
If you want Google to stop indexing your entire Thinkific site (your additional pages, site landing page, etc.) then you should add a noindex meta tag to your page HTML code. You can learn more about that process here. This will require going into your theme code and adding that snippet of code to each of the site pages you want hidden. Go here to learn more about your theme and how to access it.
Reach out if you have any questions here!