How do you know someone is Catfishing you?

This guy on Facebook started talking to me almost a year ago. Nothing major, just casual and talking about every day life. However I was feeling unsure about him in general because he had very little information on his Facebook (showed only posts from over a year ago) and just one vague picture of his face. No other pictures, although he said he has a child.

The talks weren’t romantic at all since I’m not exactly interested in dating. However he’s hinted a few times that he likes me and I just shrug it off. When I asked about him, his life etc, he said that he lives with a girl and his child, the girl being the mother of the child. He didn’t call her his gf or wife, but I assumed that it is his gf. He would contact me every day later on and share pictures of himself at work with me. Usually him sitting in his tractor at a construction site. And that’s all I know about him. He’d ask me hundreds of questions daily, wanted to know everything about me. Yet when I ask more about him he would keep it vague. For example he said he plays guitar and when I asked him (on purpose because I wanted to see if he was telling the truth) to send me a short video clip of him playing, he said he doesn’t play for people he just likes to play for himself. So again he doesn’t show anything of himself. He doesn’t talk about his child. He doesn’t share anything except pictures of his face. It was weird to me that any person who is a parent would never mention their child during their everyday life because I would assume your child would be the center of your life.
So I stopped talking to him and then started asking 3 friends on Facebook who are in his area, to look him up and see if they know him. However all 3 said they can’t find such a profile on Facebook.
So to me that is very weird. Why would only I see his profile? Any random friend I ask to look him up, say they can’t find the profile. Did he then block all my friends? And if so, why…

Also, couple months passed and he sent me a message again asking why I ghosted him. I told him I didn’t ghost him I just merely stopped talking because I don’t know anything concrete about hkm except that he has a child and lives with a girl. Other than that I don’t know anything and don’t feel comfortable sharing my general business with him if I am unsure of who he is. And he never really said anything about my response. All he said was well I miss talking to you.
I ignored it and so we don’t talk for a long time. Then on Christmas eve he sends a message again it being Christmas greetings.
I have reason to believe he could be catfishing because why am I the only one on my friend list who can find his profile, why does he never talk about his child, why does he only ask about my life but never talks about his… he seems so genuine and nice though… but I’m skeptical. I don’t want to date him I just want to know if he is catfishing me or am I being rude by ignoring him flat-out…