I was at a bar-type place at the Lester B. Pearson airport in Toronto – and when I took a seat at a bar stool with a coffee – the waiter person said something with nooby grammar like "no coffee up here – only alcoholic beverages", I then asked "must I purchase an alcoholic beverage to sit here?" the person answered "yes"

I’m 15 and I can’t purchase any alcoholic beverages! 🙁
Legal or illegal?