Craig Freshley offers a handy introduction to how to use ZOOM on his website here.
Several free conference calling services are also available, such as freeconference.com.
(Up to 50 participants free)
Google Hangouts Meet
(Gsuite basic is 6$ a month for the host, up to 100 participants, but some services will be free until July 2020)
(free for 6 months)
(free for up to 50 participants)
(Free for up to 100 participants, 40 minutes time limit)
Below is a more extensive guide expressly for dealing with the need for remote meetings in response to the current situation. It covers several other services that offer free, inexpensive monthly costs, or free trials: