Zellers, Walmart. You name it. Even Moores.
Although don’t try the dollar store 😛 if they even have any.. but usually people buy shirts all over the place. It’s just a matter of variety on which people like.
You can shop at American Eagle, Hollister, or Abercrombie & Fitch. They have good durable cotton shirts, since they are 80’s 2 ply.
Others, there are many different types of course. If you are a messy person, you should get cotton dress shirts, instead of polyester, or cotton/poly blend.
I have gotten a few unknown stains on my shirts before, and most of them come out with one washing, or if I use color safe bleach. Other than that, some stains just don’t come out, and I have to keep on washing it until it does.
Depending on where you are, if you are in the US, Europe, Asia, Oceanic lands, or South America. You’ll just have to ask people all around you. it doesn’t hurt to ask you know 🙂 I asked some strangers where they buy their shirts, and I’ve gotten good results.