felt SO weird about a party I attended

I am just gonna rant here lol because I need to get it out of my system. I am F19 and recently started college, so I have made new friends. Apart from the girl group I have (a very very wholesome group) I befriended a guy too. I do not talk to guys he is the only one i befriended and because he is very very chill. He's very golden retriever younger brother coded and we have a very funny banter all the time but he has a very separate friend group and I am semi-close to two of the girls from his group because we became friends on the first day of college itself. Now, a bit about me. Although I am native to my city, I haven't gone out too much. I have very protective parents and they're very much present in every step with me. So much that I share most of the stuff with them, including boy-girl drama around me. I've never been involved w a guy and that is where they draw a line, I respect that. They do not support alcohol smoking either (my dad occasionally drinks like once a month and he is a very funny drunk). So in short, I've been given a very very sheltered life. I was not allowed to go out much before college but as I have started travelling, they've trusted me to share where I go when I go without pressure. I tell them on my own that I am going here and they're sort of chill about it however I do hesitate if I am going out twice within 2-3 days because I feel like they're going to go back "not allowed mode". Now, today, it was the guy friend's 18th birthday. So I went there with my closest college friend since she's friends with the guy as well. Like I said the guy friend has a completely separate group and they're a very fun group, always together. I reached to the party and I almost went into immediate fight or flight mode because there was smoke everywhere. There were drinks. And not to say that these are bad people, not once forced us to do anything but I was so turned off by the whole atmosphere that I almost left immediately. I stayed with my friend for an hour or so, and then we cut the cake and left. On surface we had fun, we ate but I just felt like I was doing something wrong and I feel so fucking guilty for just being present there. I travelled across my entire city, the venue was very much far away from college and I already live 2 hours away. Right, so I travelled, SPENT money, WAS THERE in an active alcoholic party and did not tell my parents. I feel so fucking off about that, usually I'd come home and yap about every little thing but I could not today. The group is behaviour wise VERY chill, they're nice, empathetic but I felt so out of place there. I know people smoke drink all the time and no judgement (lol a little judgement for smoking) but it's a personal choice. I do not know how i feel about it anymore. Losing my mind lol. I know I'll probably be thrown into a situation like this again considering the city I am from but the first time is SO WEIRD. edit : I came here TO RANT and know if people feel the same way, idk why people are just bashing me for judging them 😭 I am not. They're my friends. Everything just caught me off guard. The comments literally say go get a pg to get more such exposure so i can be prepared for the future? Why the fuck would I do that? How do you expect a 19 year old to have a 35 year experience on dealing with people with risk behaviours? I am aware I need to learn to deal with such situations.