Well, if you're looking for Pokemon friends from all over the world, then you have certainly come to the right forum, my friend! The Pokecommunity is quite the diverse community and I'm sure we are quite pleased to have another member from China. ;D
Yes, we do have tournaments. They are located in the first link that Onveloper so kindly linked you. Right now, there are quite a few tournaments occuring such as the Extreme Speed Open, but you will have to wait for Aurafire to come welcome you for more information on that as I am personally a little wet behind the ears when it comes to competitive battling.
The Pokecommunity is a great place to spend your free time. The member base is incredibly friendly and most of us would be very happy to assist you in any way we can. That being said, don't hesitate to send me a private or visitor messege any time you have a question or would just like to have a nice little chit-chat.
Take care and have fun out there!
