I think the dad part belongs in the other forum. it's extremely complicated if he doesn't know he has any issues and once they start falling for fraudsters it's near impossible to get the money back. People will have suggestions of what they found helpful.
For teens post on the teen forum, but it sounds like you have controls already. Do check their texts now and then. As one expert said in a lecture I attended years ago, if you are preparing your child to live in a democracy safely, your home should not be one yet. You need to periodically check while you still can to make sure they aren't making life altering choices (anywhere from sexting photos, to online bullying of an unhappy peer to talking about suicidal thoughts or purchasing drugs online). You absolutely check everything they are putting on public tictok and IG where even if they delete it, if someone saved it, it can back to hurt them. They feel invincible and their frontal lobes don't fully develop until 25ish.