Well, kids are gonna wanna use social media whatever form it is taking. And generally speaking, by the time they are around 14 years of age, most kids will set up some kind of a social media account.
One good thing for parents to know is that you should insist that while the kid is living in your house, you have access to all the passwords and the administrative information on that account. Let kids know that if they want to have a social media account of any kind, that they need to accept you as part of the group so that you can see what is going on.
And make sure they know the rules in terms of your family values about what's okay and not okay to post on that account. And that way then you sort of set it up so that they know it's not private, other people can see it. And as long as they abide by the rules, they can feel free to use it and enjoy it. If they choose to break the rules then restrict their access to the account.