In need of some advice

The other day my friend added this guy to my Snapchat without my knowledge that she did it. Late that night he added me back and sent me a chat asking who I was. This woke me up so when I responded I wasn’t all there and when someone wakes me up really early I get in a mood so I didn’t respond like I should have. By the time I sent the last chat he started to ignore me. I finally went back to sleep and when I woke up and thought about it, I’m pretty sure I sounded like I was in junior high, not a senior in high school. Later that day my friend that added him told me I knew who he was, just not his Snapchat name. So she explained who he was to me and I found out that a month ago I learned who he was and thought he was really hot and was exactly my type and that he doesn’t have a girlfriend. But at the same time, someone had grabbed my phone and snapped him something completely random and I got removed. Do I just move on or is there something I can do about it? And is it weird that I am a senior in high school and this guy is 5 years older than me?