I need advice ASAP please?

so heres the thing. im in 9th grade and im a biual girl. i cant say i like her considering i never met her, but im attracted to this girl named ashley whos also bi. shes in 11th grade. anyways, yes i know this is kind of sneaky but she always hangs out with this kid named kris whos her ex boyfriend. im friends with him a little bit but anyways, i have last period with him and they always hang out together after school. so today i was talking to him at his locker after school and she walks over and starts talking to him. i didnt know what to say so im gonna do the same thing tomorrow. what should i talk about to him and what should i say to her tomorrow? i need advice ASAP...thanks:)