Let's just say things are a lot more laizees-faire.
1) GBMs
In high school there was no official word for meetings. Here they're called GBMs, or General Body Meetings. I guess now that we're in college they need to sound more official.
2) No Adults
There are literally no adults in the room. While in high school you needed a teacher to serve as an advisor, in college you need no such thing. Clubs are entirely run by e-boards, which usually consist of a president, vice-president, secretary, and treasurer. There might also be a historian and event coordinator.
3) Profanity
You won't have to censor yourself as much, mainly because there are no adults to censor yourself for.
4) People come from other schools
Representatives from corresponding clubs at other colleges may appear to tell you about their meetings or events. I mean, I'm not sure how they expect freshmen dormers with no car access to get to their campuses so this must be more for upperclassmen or commuters.
5) A lot more people
There might be so much people that you won't know everyone's names at first, but you can get to know them by participating in games and going to events.
6) There are a lot more events/sales
This isn't like "one bake sale then you're done." It's more like "multiple bake sales, and also joint events with other orgs." Oh, and you'll be hearing "Come through" a lot.
7) It may take a while to fit in.
Obviously this is easier for some people than others, but if you don't feel like they're your family yet, that's normal. Think about high school; if it took you many years, and many combinations of people throughout those years to feel truly connected and valued, it's basically like that and you're not alone. You're not going to get along perfectly with everyone and sometimes it takes time to make somewhere "your" place. Although not every person is going to love you right away, know that you'll always have allies, whether they're in this club or not.
8) You have a lot of opportunities
Throughout the year, you'll have plenty of chances to get involved. Don't be afraid to volunteer for leadership roles, or positions that freshmen rarely win. Upperclassmen might urge you to "wait until next year", but that may be because they are afraid of getting defeated by a freshman. If you believe that you are the best person for the job, go for it.
9) They're fun
Not only can some activities take your mind off the stressful parts of college, you're also creating memories that will last a lifetime.