You can go anywhere and buy a t-shirt. I think any big box store, chain store in the mall, and locally-owned boutique in small-town America will have some sort of t-shirt that you can purchase and they'll tout that it's the "best basic".
Welcome! I'm Libby, the creator of Stylin' Iowan. I hope you like affordable fashion, beauty finds and encouragement because you're going to find a lot of it here.