Do search engine crawlers build the cache?

Hi,
I have a new website online with WP Fastest Cache and have disabled the preload. However, cached versions of pages are created all the time. It is unlikely that guests have accessed this page. They are pages of a custom post type and there are over 1000 of them. I suspect the Google crawler indexing the pages. Can I prevent this? I have limited space with my hosting provider and I don’t want to keep all 1000+ pages (and also the translations into two other languages, so > 3000 pages) as cached pages.