Fabric and Textiles advisor

I am looking for a fashion designer or someone who has experience ordering custom fabric and overlooking production. I am launching a tshirt brand and i am importing custom hemp/organic fabric from overseas. I want to make sure that I am ordering the right fabric and trims amount to manufacturer the amount of tshirts I need. i want to make sure that I am following the right procedures to ensure that I get the best results and know everything that I need to know before moving forward with my order. Overall I am looking for someone who can guide me to do take the right decisions and steps as this is something that is new to me. If you have experience doing this type of work please let me know. Thanks