This is generally what happens.
You get to O-Week, a bunch of crap is in your face and everything looks interesting. What do you do? You leave on the day joining over 10 societies. This isn't a bad idea actually as you then know what you want to do and eventually you will find the perfect societies for you.
Now you get to first week and you start to think "What was I thinking joining that society?". You'll end up culling the list of societies that you stay active in to around 5 by the 5th week.
By the end of semester, you'll pick out a few standouts and either dedicate equal amounts of time to each or spend heaps of time on one and casually participate in the rest. I joined around 12 to begin with in O-Week last year, now I spend a lot of time on one purely, spending countless hours per week on it (even in my holidays!) and have 3 other casual societies which I participate in events from time to time (maybe once a month or something).
I would encourage you to join a lot then start to only participate in the ones which you want to the most as to get the big picture of everything around you. What you do with that society and how far it takes you is completely up to you.
