I don't know how to go ahead.

Times are changed, and looks like guys who wanna sentimental relatioships are marked as weirdo and boring.
So I was reading how you have to act like if you don't wanna anything for the woman who you like, so she startes to like you. This is nonsense, but I mean that kind of nonsense that actually seems to work.
But then how can I show my interesting in a determinated girl? Can I say compliments without looking like a p**sy dude, I mean a "Hi beauty" shouldn't kill anyone.

Then, I read that if you are looking for a relationship in early age it is just 'cause you are desperate (so am i) and when you taste it, you will regret your freedom. Indeed, I was in a starting long term story, but she was really chocking.
From one extreme to the other, or they don't care me at all, or that one don't let me alone for a moment.
But sure I don't like much the idea of being a playboy, but looks like if I'm not like this I won't get anything (and for being clear, i'm tired of owning and waiting).

Any tips?