Clean up of Lightroom Catalog files, what is ok to delete?

Hi there,

I would like to clean up some storage space on my Mac and I noticed that most of my Document storage is taken by Lightroom files. Could you please advise me/explain me which of these is safe to delete? There are many backup Catalog zip files, can I get rid of them all apart from the most recent one? What about the other type of files?

Many thanks,

Lucia