These important guides may help you protect your child whilst online.  They are very thorough and each section has actionable items for the parent/teacher.

https://www.vpnmentor.com/blog/the-ultimate-parent-guide-for-child-internet/

BroadbandSearch has written a more comprehensive guide available here

https://www.broadbandsearch.net/blog/online-safety-parental-controls

There’s also this link which you might find useful if you want to know more about anti-virus software https://www.safetydetectives.com/blog/parents-guide-for-safe-youtube-and-internet-streaming-for-kids/