 To find your saved citations, you need to open up Zotero. I placed mine on my desktop, but yours might be located in a different area. Now if I select my library from the menu on the left, I'll be able to see all of the citations that I've saved. And they stay there unless you delete them. Another way you can access your saved items is by logging into Zotero.org. If you've set up syncing in between your downloaded version and the online version, your library should be identical.