I am 68 and planning to travel to Guangzhou in China with wife. We are vegetarians. We like to stay in a crowded area where we can walk a lot. Also we would sometimes like to cook our food. A supermarket nearby will be to great advantage.
In addition, although they claim they are vegetarian restaurants but no certification is done. And not every restaurant offers English menu.
For supermarket, search keyword "广州 超市" in baidu map and you can find the location easy.
There are several supermarket chain in Guangzhou, including 家乐福(Walmart), 百佳 (From Hong Kong), 好又多(From Taiwan), 华润万家 (Chinese firm but cooperate with Tesco), 大润发(From Taiwan), 乐购(Tesco). You can find most vegetable and other foods you need in larger supermarket.