Yes, there are several sources of online information for Zoom users.

Harvard IT's Knowledge Base also includes some information here: https://harvard.service-now.com/ithelp/hlshelp@law.harvard.edu?id=kb_category&kb_category=e4eee578374176009aa163d2b3990e2e

The main Zoom site has a thorough manual, probably better for advanced users: https://support.zoom.us/hc/en-us/sections/201740096-Training  This manual frequently includes links to YouTube videos for instruction on demand.