The required documents for China tourist visa are as follows:
1. Original passport remaining to be valid for at least 6 months from the date of application and with sufficient blank visa pages.
2. One completed Visa Application Form with a recently-taken passport photo stuck on it.
3. Sometimes, you may asked to provide flight tickets and hotel reservation from China.
For your trip to Hangzhou, you can refer to https://www.travelchinaguide.com/package/hangzhou.htm as a reference.