As fashions change at a very fast pace, it is not economical to do registered trademarks for everything (only the business name main logo maybe slogan). A simple trade mark (TM) after the name of individual garments will do. For a license, yes you will need one for wholesale. For tags you can have the company name (if you want) but you are required to tell what it is made of what percent, the size, and how to clean it.
Well, assuming you want to make sure the clothes aren t reproduced in some way you don t want them to be, you should contact an attorney who can guide you through the process. You ll need one anyway when you want to incorporate. Best of luck!