Often, fashion designers would register their company name but then it takes them 6 months to 1 year to launch their fashion line.
And during that time, what if someone else trademarks your brand name, then you can not use it.
To be safe, I would suggest that if you have decided on a brand name and know that it is available, file for “Intent to use” trademark, especially if you are few months out from your launch of your fashion line.
Trademark protects your names, symbols, logo, words that distinguish your business & brand. Typical costs for filing a trademark is around $300.
USPTO shares details and forms that are required. You can check them out here.
OR, if you have a lawyer, work with them to file this for you.
Rogueline approved lawyers: