You may be hearing a lot about the importance of citing sources and not plagiarizing, but when should you cite? Cite when you:
If you're not sure whether to cite something, check in with your professor or librarian, but in general it's always safer to cite!
If you have a Chromebook, an Android device, or don't want to install a program, you can still get many of the benefits of Zotero by using ZBib. Zbib allows you to make a bibliography in any style by adding the URL of your item. It won't help with in-text citations, but it still saves a lot of time!