I hope once you figure out how to outsource the business logistics of screen printing on demand with quality materials, you have another design that gets good traction. If you are trying to figure out how to get your work out on clothing, please make sure you put effort in selecting quality materials so that not only does it look good, it feels good.

I'd avoid genetic cotton in general and opt for a blend with polyester. The softness and stretch will make it a quality shirt people will wear over again, rather than some shitty bottom barrel cotton shirt that looks cool but doesn't fit well.

You've got something here bud. Good luck!