achieve... what exactly? Just say hi, and smile... compliments are good too. Just treat her like a person you want to be around, not a GIRL you want to be around, that huggy/kissy/teenage stuff will happen if it's gonna happen, you just need to break the ice, ya?
talk to her. Ask her questions about her self, listen to her answers and ask more questions based on what she says. That's the sum total of my knowledge on conversation.
yeah u gotta start somewhere. the longer u leave it the more weird it will be when u suddenly say hi.