Replying to T-shirt help

Hey guys, I'm entered into a program through school that grants myself 1500$. With this 1500$ you have to become an entrepreneur. I was thinking of doing my own clothing line, i would use shoptify( i understand all website related things.) I was researching but i can't seem the best way to go when getting my logo printed on my clothing. What are people's suggestions on what way i should go about doing this with 1500$. I was playing on using gildan clothing as their cheap and somewhat great material. If someone could help out that would be great.