The first time your Zotero library syncs, Firefox may appear to hang, especially if you have a large library. Be patient. If the Zotero sync icon continues to spin and you're convinced there is a problem, see Sync Queuing.
By default, Zotero will merge your local Zotero library with your library on zotero.org—any changes you make in one place will be applied to the other and on all other synced computers.
There is a limit to the storage for the free Zotero account. Currently, free accounts allow you to have up to 300 MB of storage space. If you are interested in storing the PDF on other cloud services, please consider using ZotFile to route your PDFs to a folder on Rutgers Box or other cloud-based management systems. By downloading Rutgers Box Drive onto your computer, you can easily access the files on Rutgers Box.
Without a paid account, you will exceed 300MB of storage space in no time, especially when you plan to store the full-text PDFs of the citations. You can consider installing ZotFile, a third-party plug-in for Zotero to manage your PDFs. Learn more about using the ZotFile plug-in!