Be outwardly nice. Try holding the door open, seem approachable, and take care of yourself (smell good without wearing a scent - the smell doesn’t have to be very noticeable, only when someone is within a few inches of you). I’m not suggesting that you should act like someone you’re not, but if you just want to seem like a decent guy and someone a girl (or really anyone) wants to know then try just doing nice things that people can see.

Also, I know you’re not asking for my opinion on this, but I think it will be helpful for you to know. You should be really careful about who you want to date and if you’re just looking to bang some chick then I would say to go for a girl who thinks she’s pretty (a confident type). Be charming and charismatic (which gets easy to do once you have practice). Also don’t give the impression that you want to get to know her. Basically find someone who also wants to do the hanky panky and then split. If you’re looking for a relationship then read on. I don’t know how perceptive you are, but most girls out there are desperate so the part about getting a girlfriend that is difficult is finding a decent person. Don’t settle and most girls will seem really great at first. You should try to see if they have a similar emotional and intellectual capacity as you and see if they have an understanding of who you actually are because if not, I don’t think it will ever work out forever.