There are noodles, rice dishes, stir-fry dishes with various local characteristics, as well as various snacks, hot pot, skewers, spicy hotpot and other delicious foods. There are so many Chinese delicacies, it depends on what you are looking for.
Generally, there are shops selling popular food and snacks near large shopping malls or schools.
Now I recommend a few similar places to check out, such as Wanda Plaza near Tongzhou Beiyuan, Roosevelt Plaza at Nine Trees, Xinhua Street Food Street and Liyuan Subway Street, which have not many street shops but also have many.
There are also many gourmet shops scattered in various places waiting for diners to discover by themselves.