Most of the children around here get their first smartphone at the age of 12. At school they get thaught about the risks of the internet and social media but parents are also asked to guide their children on this path.
Before that age most schilderen have access to a tablet and the advice there is to only let it be used in the places where you as a parent are present. Not in their room for example. You don’t have to hover above them but just being near and checking the tablet every few days or weeks will do.
Same with gaming consoles or computers. We have them in our living room so our children only use them in those spaces where other people can be around. That way we can hear their conversations and intervene when their are getting too loud or make sure they use proper language.
No real software limitations apart from adblockers. I did block a whole list of porn sites when they were younger than 12 bit after that age I took away all the restrictions on my router. We had a conversation on the impact and consequences of porn but they will be curious and will find or encounter porn eventually.
So, I would say. Teach and supervice your child and make sure they have the appropriate age for or are to be trusted with their devices.