You are correct, there are lots of students that are unsure of what they want to study. You are not alone. It is not uncommon. You will be ok. However, rather than saying what you won’t do, keep an open mind. There is nothing wrong with going to a party. There is more that goes on at a party than drinking and “hooking up.” Definitely, no smoking or drinking, but you can dance, talk, and people watch.
Others have stated you should join an activity group…I highly recommend that.
I think you will be fine wherever you go. Godspeed.