If you need to hide pages from search results, start by adding a "noindex" tag...

https://www.tumblr.com/distantlyperpetualharbinger/811808907244797952/should-i-block-a-page-behind-a-login-to-remove-it

If you need to hide pages from search results, start by adding a "noindex" tag to the page header. This tells Google to drop the URL from its index naturally. For urgent privacy needs, use the Search Console Removals tool to hide content quickly