Hi, not going to bore people, short and sweet

I met a girl last weekend, we clicked, held hands, she was flirty. I had to go elsewhere during the night before I could make a move. when I went back to meet her few hours later, she was with another dude. When she saw I had come back she tried to get my attention again but I wasn't to impressed. I left, she told me to text her and go out again next weekend with them. Later that night as my night was ending she msged to say sorry that she was annoying, and it was great to meet me. I replied saying she can make it up to me next time.

Main thing to note is that she is 18, which I did not know till later. I'm 25. I'm not looking for serious and I've been told shes kinda a player. So is this something I should stick around for if I am just looking for fun, and if so, should I make a move? and what move? I was in a LTR for the last 4 years or so, and I've never had something like this so I feel pretty lost on what to do