jszymborski parent
Zotero can't extract references from a paper to read later, or at least, I've been using it wrong for years now.
There's a plugin that can do this. It is a little rough around the edges but can extract references from the pdf and search semantic scholar / crossref with decent reliability.
https://github.com/MuiseDestiny/zotero-reference
As a disclaimer, I am not associated with its development.