My kid met someone online in a game and it made me paranoid

So my 10yo was playing some Mario Kart thing on Switch and got a friend request from someone who was "nice" in the lobby. Didn't accept it, which is good, but when I asked him about it he was like "why would they be weird?" and I realized I never had the talk about online predators with him. That was a wake-up call. Had the conversation yesterday (tried not to scare him) and now he seems anxious about online gaming. How do you teach them to be safe without making them paranoid? This is new parenting territory for me tbh.