Lithuanian for tourist VOA

hello there,
i want to travel China for 2-3 months after visiting Thailand and I want to avoid visa hastle in the embassy. Can I fly from Bangkok to Haikou, obtain 3 months VOA and continue my journey to mainland by train? first visiting Guangzhou and surely many more visits on the way.Thinking to have return ticket to Bangkok with 3 months gap. Do I need to prove were I gonna sleep all 3 months? or can I show the hotel/hostel booking in Guangzhou for the first 2-3 nights and they would be ok to let me go?