Should an undergraduate writing an article for a semi-academic magazine list a university affiliation?
Grad students often write "PhD candidate" on their websites, etc., so you might consider "Yuhao Dong, BSc candidate, School of Computer Science (or whatever your department is), University of Waterloo".

Edited to add: I was curious, so I checked the author guidelines.  They don't indicate how to specify your affiliation, so I would either ask the editor or look at some articles from the most recent issue and copy their style.