How can I get closer to a girl I’ve never talked to before?

Maybe I’m too young to be thinking about this stuff right now, and I hope I’m not just a creep.

I have 3 classes with this girl, but math is the only class where we sit next to each other, we haven’t talked all year except us asking each other short questions, like what’s the time. And in a flash the school year’s almost done. We most likely won’t have classes next year, I heard her tell our teacher she’ll take advanced math next year.

I’ve looked at other… reddit posts.. about stuff like this. I don’t feel like just saying something like “hi” one day randomly would turn out very well. I’m not a very confident speaker.

I don’t know what a good “excuse” to talk to her could be. There’s not much to talk about in math. I feel like just being friends with her would be nice.