Definitely play every style of game you game, you'll need all the skills. If you're on location, only play one game and then move onto another style one, that's how it's going to go. And when you find a game you've never played, pretend that game is all you get and see how you do. Many of the games, you (and people in your group) have probably never played, let alone know well.
I had a great time last year as my first time. I found the vast majority of players very friendly. Even the ones that were more serious were still friendly between games and afterwards, just focused during each game. Most were willing to chit chat between balls but generally didn't share any strategy until after the game was over, and then were more than willing to explain parts of the game.
I will say though it gets harder the later the rounds get so just keep at it. By the end you're playing with people almost exactly as good as you, which I think is pretty amazing how that works. I know I started getting a bit overwhelmed (and tired) day 2 and had to remind myself to just have fun.
One of the best parts I think is getting to play with the variety of players. I'm still learning so playing with all the better players is really neat and I was amazed at how sharing and support most people displayed. Many times it was more us against the machine rather than against each other.
My best advice is just have fun. And if you find you're not, try and figure out how to get back there. After all, you get to play pinball all weekend on hundreds of machines! (and arcade machines too this year)