Depends on age and maturity.
When given access to computing had discussions about finding things you may not understand or extreme weird things - and that he/she can talk with us to discuss these things.
We occasionally look at url history to this day.
later showed how to use multiple sources to check for accurate info and showed how mayo clinic, webmd, a few others may offer different details.
Showed articles from the news where people stalked and tried to kidnap based upon online chats.
Did research on software - used family-link on google to block things until age 13 when family auto-destructs.
Had discussions every few months about how people show edited bad things to get others to to bad things - story about the 'bernie sanders freedom sticks' - other challenges' where people got seriously hurt or killed.
Talked about how sharing a picture could give you your exact location in multiple ways.. and if other details were known like time or whether or time school starts, how that process is easier.
Decided Disney cirlce's dns poison on the router and via app on the phone is the best censoring we could find. Then found out we can't afford it.
Found out other kid never uses youtube on his phone and cant use directions apps cuz the family link from google.. found out other kid tells that kid to install amino chat(?) and it iframes youtube (non-kids version) - they are hackers already..
Show article from yahoo news recently about the grooming kids via list of apps, getting them to send pics, then blackmail for more - depression and crap.
Show them that anyone can voice change and appear to be a girl or kid using phone apps and even method to do so on playstation mic.
Show how I can use a cam plugin to show "live cam" form my system, which is actually some random girl not me..
I have been considering getting some people together to build an app that semi-spies on kid's audio - and auto erases 90% of it.. and only sending a notice or save if it gets hits on certain keywords.. and make that toggle-able for various parents.. some might want sex keywords.. I think suicide related ones would be pretty universal.. but able to toggle others.. some parents no cuss words.. it's still various napkins of ideas.. something maybe with mycroft or similar that does not send audio to the cloud..
Keeping an ear out... my stepkid can and does tell me various things that are going in his digital world and I cam always accepting / listening, not getting angry - and I offer counter info on occasion..
The surprise I had when I found that a meme-thread-group was pushing extreme anti-feminist stuff... I did not show my emotions, I instead offered multiple other viewpoints and said perhaps reality is in the middle and there are extremes and edge cases here and there that do not represent the masses..
Looked into the open source disney-circle like thing - could not figure out how to make it work after studying a couple hours.
There have been more things over things, I'll try to remember and add.