try typing this in google maps. it is on minquan and the school is at the edge of the street. its only about two blocks long. lmk if you go, the owner of the nicer shrimp shop still remembers me.
SānMín Elementary School, No. 1號, Section 5, MínQuán East Rd, Songshan District, Taipei City, Taiwan 105
if you have a car, there are other fish store streets in the suburbs outside of taipei that are much bigger.