I adapted a method from YouTuber “morganeua”, described here.
Some of this probably isn’t relevant to you, but it might be a jumping-off point and might be useful to other readers.
Each source is its own note. Personally, since my PKM is all about academic research and I’ll eventually use Chicago Style citations, I title each note (Author, Date). If I’m sure I’ll be using that source in future then I go to the trouble of formatting citations for footnote bibliography and paste those into that note. As I write the components of my paper in Obsidian, I type [[(Author, Date)]] so my paragraphs display (Author, Date).
The reason this works for me is specific to the rest of my process: I “build” my papers like a Map of Content (MOC). Each note is titled with its argument / main idea / thesis statement, and I arrange those in a MOC note as an outline, so I can see that my paper is well-structured. After the structure is good, I grammar check each note, and once it’s all ready to go I paste it into a word processing program. That final step is when, in the word processor, I replace each (Author, Date) with a footnote, and it’s handy that I have the footnote and bibliography immediately at hand, linked to the Obsidian note from which I’m copying my text.
I can also then see, via backlinks, what ideas I’ve used that source for.
Since my PKM is very strictly “note making not note taking” (as Nick Milo puts it) or “write in your own words” (as “Morganeua” puts it, which I believe she gets from N. Lumen’s Zettlekasten method), it’s worth it for me to take the time. Anything not worth “tracking” in this way doesn’t need to be in my PKM.
What you’re describing might make Readwise Reader a useful part of your process. It automatically generates a sort of citation when it imports stuff. I have had a complicated relationship with Zotero, it fails more often than not, and like other researchers have sometimes chosen not to use it at all or not to use its “automatic” features.