Many people say that Chinese is the most difficult of all the major world languages; however, it is also true that many people have learned to speak it successfully as a second language.
The first difficulty is what is meant by 'Chinese'. There are many varieties of Chinese and they are very different from each other; it's the written form of the language that remains similar. When people learn Chinese they usually learn Mandarin, the major form of the language.
Another difficulty is that Mandarin, like other tone languages, uses changes in tone to mean different words, and it can be very difficult for foreigners to hear these although children usually pick them up quite quickly.
The written language is also difficult with an extensive and complicated system of characters. However, if you persist you can learn the language, both spoken and written. You can get some ideas about learning Chinese here.