Can we use the Present Simple in this sentence : As you know, I try to learn Chinese. Or is it better to use the Present Continuous?
With the verb try, the simple present I try does not refer to something you are doing now, at this time in your life. Rather, it refers to an effort you always give.
You mean "now", and so for that meaning you would say I am trying to learn English and chess.
You have decorated the place very nicely for the party!
-- I try.
There, I try means, "I am always willing to put in a good effort. It is in my nature to try to do a good job."