Well, i cant tell if she likes you from that, but your best bet is to see her again

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okay so no, it is not weird to invite her to your house. You could go bowling, that is always fun, or to the park.
See her a few more times, and then just let the conversation flow and say i really like you. the worst thing that can happen is she says no, and then you move on

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If you text her a lot, she will text you first if she does feel something.
NO, call her to talk randomly, that is very nice!

. just talk about school, life etc!
Rather try to have deep conversations over the phone / IN person rate hr than over TeX messages, but if you must, just bring up something, like your parents divorce or something, and let it flow.
Just text her as much as her replies are interesting, if she seems bored, carry on another time.

any more advice: I'm also in high school, never had a boyfriend, but if it doesn't work, dint stress, we have lots of time

hope this helped