Your website allows you to toggle index/noindex and follow/nofollow for each page and post.
You can find a full description here, but basically, "noindex" means that search engines won't crawl and index the page, and "nofollow" means search engines won't continue following or crawling any links it finds on that page.
To toggle these settings, find the "Robots Meta" box on the page or post you want to update:
If you can't find the Robots Meta box, make sure it's being displayed by clicking on "Screen Options" in the top right corner:
Then, check the "Robots Meta" box:
Once you've changed to the desired setting, update the post/page.