Alpha males and females are very real thing in our society. So is the Beta and the Omega. Just look around your workplace, school, home or wherever.Alpha male doesn't even make sense in human society, unless you're talking about a father as head of household or a harem lord or the leader of a gang or something; the term has been bastardized by so called "pick up artists".
Yes, confidence is sexy, whether male or female. Sometimes you can make other people feel confident and comfortable and that should really be your goal with people you like and want to learn more about.
They are easy to pick out if you look carefully.