how i can apply for chinese visa and what type should I apply?

Ali, you should apply for a proper one according to your purpose of visiting China. For example, if you go for a trip, a single L type is ok. You need to prepare your passport, filled application form together with a recent passport photo, round-trip air tickets and hotel reservation. If you come to China for the first time, financial status is required, such as your bir-stamped tax form, employment certificate, professional ID and recent six months bank statement.