Is it normal to contact long lost friends on social media?

I used to be friends with this guy in high school 6+ years ago and we had classes and rode the bus together, and talked on the bus nearly every day. We were never really close or hung out, but we would have nice conversations and although I felt we clicked pretty well, we lost contact after high school. I was thinking about our little group that we rode the bus and talked with the other day and wondered about him, and decided to Google him to see what he was up to these days out of curiosity, and he has an Instagram. I would like to just say hi and ask how he has been, but I don't want to seem weird or creepy, especially since it's been so many years since we last talked and we weren't very close or anything, just kind of chatted on the bus every day. I'm also afraid that with me being a girl and him being a guy, it might come off weird or awkward. Maybe I'm thinking too much into it, but I just don't want to create an awkward situation or seem like a stalker. I know people reconnect with old friends and acquaintances after decades on social media, but I just want to make sure I'm not overstepping any boundaries or anything. Thank you!