Should I pay for these girls at the movies?

I am a freshman in High School. My friend (guy) and me are going to the movies with this girl, and two of her friends. I reallllllllllyyyyyyyyyyyyy like the girl (lets call her Kathy). Kathy is single by the way. Kathy and I are not amazing friends, but we text each other and occasionally talk in school. I asked her if she wanted to go to the movies with a small group (to try to get to know her more). She said yes. We are going to see a movie this coming weekend (either Friday May 8th; Saturday May 9th; or Sunday May 10th) Should I offer to pay for their tickets, food, drink, etc. Or do you think that it would be weird or inappropriate to pay for them since I'm not dating her.