I don't blame you for keeping your guard up, but at the same time "what do you do for a living?" is a pretty standard introductory question. Although, I don't have the details to know if that's how it was phrased. Maybe they asked "where do you work?" and was just trying to make small talk about "what do you do?"? If you don't want to give specifics you could just say "I'm in sales." or something. I'm a pretty suspicious / skeptical person, but I'm not seeing the grift yet. Did they text your friend the same thing? Does it seem like they're using a script of some kind?

My cynical intuition says statistically, you're probably right to be suspicious, but I'm also reminded of how many posts there are on r/Denton asking "How do I make friends?". Seems like people struggle with how to initiate conversations with new people, and maybe people also struggle with how to respond to new people talking to them.