Some of this advice is just plain terrible.
How good, or bad, you are on a play site never, ever, EVER matters when it comes to playing live in a casino. Yes, some skills sets involving patience and discipline would seem to count, but even they don’t since players on free play sites are practicing those skills against the skill sets of other free-to-play players.
Earning a million, a hundred million, or even a billion million chips on a free sites means squa-douche.
Thinking it does will just mean you will assume you know things you don’t, that you are better than you are, and even worse, will jade your ability to read opponents.
Instead, follow this easy recipe for your first time.
1.) Pick the game you are most familiar with in the style you find the most enjoyable (i.e. tournament or cash game). Limit or No Limit are a matter of personal taste.
Do not worry about “rake” or “sharks” or what have you. You want the experience, not an income supplement. Most sharks don’t fleece you right off anyway, since they take about half an hour or so to get a read, at the earliest, and even when they have you dead to rights they do not want to scare away the other fish.
Besides, it is possible, depending on the stakes and the casino, that there won’t even be a shark present. Best table in the universe for fun-playing! xD
2.) Be friendly and tip the dealers.
Make sure you inform the dealer you are a n00b, you will need the protection from sharks and asshats while you are learning. Make sure you tip the dealer(s) periodically, and be friendly and non-argumentative.
A good tip ratio depends on the stake & rake, but since I told you not to worry about the rakes (xD) just pass the dealer a SB-size tip whenever you at least double your investment in a pot (excluding the initial blinds), and give him a BB-sized tip when you are super happy your pocket 10’s cracked Aces or Kings, or you otherwise feel beholden to the dealer for making you an A-Perfect River Fish. 
For emphasis, this is very important. In the past I have seen dealers and managers be very protective of their players, and it doesn’t take much to gain this edge. Everything from making a mistake when betting, to having opponents try outrageous angle shots, to outright belligerent behavior is all easily handled for you if you have friendly staff around.
That being said, don’t go overboard on the tips. Just be friendly and everything will be fine.
3.) Play within your limits, don’t spend money you can’t afford, yadda-yadda-yadda.
4.) Have Fun!