These instructions are for when you're only trying to create a bilbiography (not writing a paper where you're including references throughout and then creating a bibliography). The video below shows two different options for doing so - one if all of your citations are mixed in with other ones, and one if you use folders in Zotero and have all the necessary citations in one folder.
You can either watch the 2-minute video below, or read the instructions below that - they cover the same material.
Instructions if you have all your citations mixed together in your Zotero Library:
Instructions if you have all your the citations you need in one Zotero folder/collection:
Much of the time, you're NOT only creating a bibliography - you're also inserting parenthetical references or footnotes throughout a paper, and then including a bibliography or reference list at the end. This video should walk you through those steps.