Literally the best approach to your problem is to just jump in. Talk to people, make connections, try!

No simulation or amount of advice can really prepare you for an experience. You could get an idea, but in my own experience, going into these things with a lot of expectations can just ruin them.

Yeah, it's intimidating and scary, but it literally always will be. You just need to get over that hump and start getting your feet wet. Socializing is just a game, and failure is the best teacher.