Need some advice to help my friend. (slightly serious)

Hi guys, sorry for the long story but it will make sense why if you read it. But anyways this is really important to me so I'm going to get straight to the point.

About a week ago a new kid enrolled at my school, which is pretty cool and exciting because I go to a relatively small school and hardly get to meet new people and whatever.

I and my friend group noticed though that he was sitting alone at lunch and even in classes, and seemed to be relatively ignored by everyone, gaining our sympathy. We, being the extremely tight friend group that we are hesitated at first to invite him over. But just the other day we asked him to sit with us at lunch and during classes.

He was relatively quiet and did not laugh or talk nearly as much as the rest of us, thinking that he was just shy or whatever we simply ignored it until he started joking about weir things and started asking us even weirder questions.

Brushing them off as a joke as well until he asked "yo' you guys know if I can get away with smoking in the bathroom?" which honestly made things pretty uncomfortable, and I just brushed it off with a joke and while everyone was laughing he asked "yeah, lol but do guys like smoke weed? like legit I really could go for some or just coke, if you know what I mean" he says laughing.

Thinking he's joking we laugh too but then my other friend says "dude, wait do you smoke weed?" again completely joking but he answered anyways with a straightforward "yeah, why?". We again laughed it off but it still makes me uncomfortable and especially scared for his own well being, considering how strict our school is.

I'm sorry guys I just want what's best for him, even though we technically just met. And I know that this post will more then likely be taken down but it would be great if you could somehow give me advice or whatever to help him or even just relax the situation. Thanks ahead!