You can take a train from Kowloon of Hk to Guangzhou east railway station first. Then take bus no. 271 to the Zoo which is just about 110m away from the city's Ocean World, so you may just walk there. I advise you just stay a hotel near the local East railway Station like Ramada Plaza Hotel, Nanyang King's Gate Hotel or Home Inn (Shengdi Square). For vegetarian food, you can try 怡新素食 on the 4th floor of Zhongtai International Square, No.161 of Linhe West Road.