How is that a weird classmate situation!? haha that sounds to me like you just had a normal conversation with a friendly person. don't read too much into it!
even if she was flirting with you with smiles and body language in general, its not time to overthink this, don't get attached to the outcome. you dont know enough about the situation, maybe she's like that with everyone, maybe she likes to get guys to like her and never acts on it afterwards,
for all you know she might be in a relationship, she might be gay, whatever!
when you are just meeting a girl your best bet is to play it cool, have an attractive attitude and DO NOT TRY ANYTHING yet.
think about it from her perspective: if you try to game her now, all she will see is a guy who is so desperate, he will try to seduce any girl he can, not caring about who she is as a person, and thats profundly unattractive.
so what you have done so far is very good. I think this comment in particular was genious:
Me: See, you weren't even paying attention hahaha
on the other hand, you created a little awkwardness when you said
Me: Well maybe we can meet up and I can copy your notes down to study for the test.
asking for a meet up is going a little too fast, thats why she came up with the excuse of her phone being dead. probably unconsciously.
that being said, you are doing great so far. but if we measured your progress seducing this girl in a scale from 0 to 100 you probably have no more than 3 or 4 points.
and its not your fault, its just that school is not a good place to seduce girls, nothing is set for you to do so. game in school is all about creating interest in her, that can be later harvested in other places like parties and hangouts with friends.
so what you wanna do it be attractive, be mysterious, be flirty, and don't show interest. in one word be cool.
the text you wanna send in my opinion is:
hey please remember to bring the math stuff tomorrow so i can borrow it and make a copy
its (your name).
of course send this the day before your 9am class.
what would be cool here is if you have a copy machine in your school, to get her to come with you to the machine room with the excuse that you have to go right after that to some class, or simply if she's friendly enough, so you wont have to go by yourself.
the key to classmate game is not to game the girl, but to make her want to game you. this is achieved mostly throw buzz, that is, through other people talking you up to her about you when you are not around. (please don't get your friends to do this on porpoise, thats counter productive, what you want is for people to like you enough for this to happen naturally.)
hope this helps mate, and as always, if you need any more advice send me a pm,
Jason