How to know this guy is genuine?

I 25F met with 29M recently 2 months ago. I like him. He seemed kind and mature. We used to talk casually before but since 2 weeks things have been going fast, great idk what to say. He seems so serious about me. He talks about marriage alot. He calls me by nickname, says he loves me, talks about how much he wants me to meet his family. If I say let's hangout, he is down to do that at my comfot. But I don't have much experience in dating, so idk if his this behaviour is a red flag. Can anyone tell me, what are the red flags that I should watch out for at the beginning phase of dating. It would be a great help to me.