How do I make myself look attractive to a guy

I feel like no guy has ever found me attractive, I’ve never dated anyone and I feel as though no guy has ever looked at me and liked anything about me
I’m just wondering if it’s my hair or my personality or what it is that makes no one ever like me
I’ve asked my friends and they say that I look pretty and an 8-9/10
But then a guy said I was a three or four which made me think if my friends were actually telling the truth
I know sometimes I come across as a rude person because I don’t smile as much but it’s just my resting face
But when I look at myself in the mirror I don’t think of myself as ugly like maybe a 7 so I don’t know why the guy said that then