Golf company: first stop, T-shirts!

Sup,

Starting a company in the golf industry, the first line of product is going to be t-shirts (simple i know). However I plan to make this project more of a learning experience - "lowest apple." I've been involved in app projects, and music projects - although have never launched an e-biz 100%

Can anyone provide me with "steps" that I should take to get from point A to point B? All I have is the idea/t-shirt designs..

Thanks!