I play cards here in Vegas on a very casual basis. Maybe twice a month, I used to play about every other night though before I met my wife. The card rooms are just like anything else, you will have your experienced guys who play tight and grind it out, you will have your wannabes that think they are the next Chris Money Maker, and you will have the tourist just looking to pass the time. Sometimes the new guy wins all the pots because they play very loose and bet on everything, even if they don't have a hand. This makes it hard for the more experienced guys because new players don't really play on logic, they just bet on everything. Sometimes the newbie will catch a great string of cards and drag some very big pots, you just never know. Long term though the experienced player will have the edge, no doubt. Just try it, you will like it!!!
As far as showing your cards, YOU NEVER HAVE TO SHOW A FOLDED HAND. I never show a folded hand, always keep them guessing. One thing to consider, if you show one person at the table your hand, you MUST show everyone else, keep that in mind.
edited to add: Iamblades beat me!!!!!