fake it until you make it is actually decent advice here, people are naturally attracted to confidence. that's not to say you should become an arrogant *******, and some chicks will actually find it endearing/humanizing if you just say "i'm pretty nervous but..." because chances are, if they're kinda into you too, they're a bit nervous as well the point is to be honest. none of these bullshit stories or ploys to get a girl's number or start something. that's usually where the whole "friendzone" (don't get me started on that but y'all know what i'm talking about) miscommunication begins.
"hello i think you are an interesting person can i have your number" it is literally that easy boyz