You need to apply for a Chinese Tourist Visa(https://www.travelchinaguide.com/embassy/visa/tourist.htm) and it can be applied by your friend in Kuala Lumpur. For visa duration, generally, you will be given a 30 days visa, or 90 days. But you can try to apply for a one year multi-entries visa with 90 days each entry. keep in mind you may not get the visa as your wish, the visa entries and duration will all up to visa officers.