In reply to jenniwat001:
Read the guide book.
See what gear you need, sport, trad or a mixture. Rope length is important.
If mutipitching, make sure you know how to get your self out of the mire if it all goes wrong, to err on the side of caution don't attempt anything you can't reverse somehow. Also a really good plan to carry a spare belay plate and tat/prussik/slings.
Be willing to leave gear behind if it all goes wrong.
Tie a knot in the end of your rope at all times.
You probably are aware of the skills you need - threading ropes through bolts, abseiling, setting up belays etc. Make sure you are good with them.
Other tips:
Insurance that covers climbing
Mobile phones that work abroad
Carry shoes and harness in hand luggage (incase main bag gets lost) - ropes and draws etc can be an issue in hand luggage for some border/luggage inspectors.
Clip sticks can be a god send for many reasons when sport climbing.
Even if it is a sport venue, some areas are made far more comfy with a small rack of wires.
Enjoy your time, relax and think about what you do and double check what you have done twice before commiting.
Oh, and don't assume in situ stuff is safe.
Have fun, be safe, Kev