I need a 2nd opinion

So Saturday night I’m driving home from work, I get a FaceTime from a random number which I then decline, then the same number proceeds to call me 4 more times in a row within a span of a minute, I finally decide to answer and a girl picked up the phone, after a bit of back and forth she finally told me who she was, I know of this girl but I’ve never spoken to her or her friends, so I’m confused on how she got my number which I proceed to ask, she then tells me that someone I knew when I was 13 gave her my number, weird right. We then proceed to talk back and forth for a few minutes about why she was calling me, which she gave no direct answer, just beating around the bush, then on the phone she request to follow me on instagram along with her friend requesting to follow me, at this point I thought they were just messing with me and I hung up we phone. Then yesterday night I’m sitting in my car and she calls me again, this time with a different friend, we continue to talk for a few minutes just like normal and she asked me where I was going and I told her I was going to a gas station near our house, she said she was gonna come but then her friend she was with wouldn’t let her come because she was driving, we then talked about a certain movie that was out and how I wanted to see it, she then said we should go see it tonight or tomorrow, I don’t know if she being serious or not because the only time she really answers me is when she calls me , if I call or text her I never get a response, I’m an 18 year old male with previous relationship experience and I’m still so confused, is she trying to give me hints or just messing with me, 2nd opinion?

TL;DR: girl I’ve never talked too but that I know of got my phone number and is now giving me weird signals and idk what this means