The 3 most common technical issues with any web conferencing software are:
Participants can't see
Participants can't hear
Background noise & mic feedback
It's important you prepare yourself and your students to overcome these through self-troubleshooting.
Consider making a copy of this How to Troubleshoot Your Zoom Experience guide and sharing it with your students. You could even add your institution's other tech support contact information to make it an all-in-one reference sheet.
You could also hold an introductory class session to help everyone practice logging on, troubleshooting technical issues, and getting used to the features you might want to use, such as shared annotation or polling tools.