I made really good friend but people are thinking different.

So there is one friend( a new classmate) I made in class. We became good friends and we are good friends. Today two of us went to buy books for school and she suggested we should go to eat something or go on coffee but we ate food at a fast food restaurant (I bought her food cuz that's what I do for a friend when I go with them for the first time). We sat in the park and chatted. My classmate (that classmate is friends with her)thought that was a date and idk how he got that information but whatever. Then that classmate said that I am her heat and she was smiling and laughing. After class, I told him that it's not okay to say that cuz we are friends and he said she might like you. Tf you mean we've only been friends for 4 days 😭 I am in high school and a lot of other people also think there is something between us.