Girl writing notes to my bf???

So my bf and I are both seniors in hs at a really small private school. In fact, it’s so small that everybody knows every one and talks to them at least once a week I would say. With that being said, there’s this girl that not many people at my school like and I think she’s in 10th grade/ 15 years old. She has a little clan of like 2 other girls and her, but she “kicked one of them out” of the group and that girl started talking to me. She told me all about how that one girl who not many people like, let’s call her K, would talk bad about me and my best friend for being so happy all the time and me and my boyfriend because supposedly “I’m too innocent for him”. Anyhow, K apparently slipped a note into my boyfriends backpack the other day that said “you should smile more :)”. I didn’t know about this until the girl that was friends with her had told me and I asked my bf and he said he saw it but just threw it away and didn’t even bother telling me. K also tried texting my boyfriend the other day when he had to unblock her number to ask about homework assignments. Y’all I don’t even know what to do abt this because I’ve never been in any kind of drama before and this is ridiculous 😂😂