Eh I think with time you'll learn that there are plenty of people who don't smoke/drink yet are still very active socially. Just a matter of finding them!
I'm the eldest of 4 girls, aged between 32 and 23. My mother has been a pack-a-day smoker my entire life but has had maybe 20 alcoholic drinks total in that time as she very rarely feels like drinking. My father likes his bourbon but has only ever drunk very lightly, again that's just his preference. Two of my sisters basically don't drink. One has no interest, the other can't stand any alcohol taste except lychee liqueur, and only very very lightly used at that. So she can have fruity cocktails using that liqueur, now, and does very very occasionally. She was thrilled to find one she could drink as she enjoys the look and smell of my cocktails, just could never abide the aftertaste.
My other sister and I drink, or don't , as we please.
I never have and never will smoke, same for my sisters. After drinking occasionally (legally) before I was 18, I didn't really drink again until I was in my mid 20s. Just was busy sorting medical stuff so not inclined, really. I did used to joke about how much I valued my brain cells if acquaintances pushed me to explain why I wasn't drinking, which was kinda obnoxious of me but well.. they started it, and it was true. After I was better medically, I found no issue with occasionally drinking, though never did so to "fit in". I just like the flavours.
I don't get hangovers or any negative effects, though my accent becomes more clipped and british - that's by default whenever I'm tired/sick/stressed/distracted though, so it's a joke but not really accurate to say it's because I've had a drink. I can outdrink most people who haven't pickled their livers, though I don't often do this. Just no benefit, but then there's also not discernible "cost" to me from drinking, it's the same for me as eating chocolate or cake - and I really need as many calories as I can get, so no concerns there.
We have always had plenty of alcohol-free friends. People choose not to drink for many reasons and I would never judge someone on their choice. I would judge them for being preachy or pushy about their own preferences.. but that's it.
Do what works for you.