I'm going to agree 1000 percent with Kushaan and just kind of continue from his comment on budget. Yes a small investment to start a budding business will have to be made, but you can also do this in small increments.
For arguments sake lets'say you're not designing the actual clothing but rather a small accessory such as a scarf. You can likely seek out the fabric at a fabric shop or on line, buy a small 3 yard piece and craft your scarf by hand all for less than 30 or 40 dollars. You can then design your business card as simple as just your name and the name of your brand in simple black and white, and buy 100 business cards on line for 10 or 20 dollars. You can launch a free website on wordpress or wix and these are drop and drag construction so you don't have to know code, and launch an Instagram account.
Take your phone and a friend and your scarf and take some photos, post them to insta, do your marketing, post to your website, announce for sale, sell the fact that these are hand made custom order, because in your effort to keep costs low by doing things by hand, you spin that as a positive (People don't have to know) and make that the important fact. Set your price, get an order do another one or two and so on.
The most important thing about starting a business is failing. Yes, failing, falling down, messing up, and just down right being disappointed about it all. That's where you learn, that's where you figure out how to make it better the next time, that's when you seek out answers, or help to things you weren't planning for. Basically it's okay to fall down, you learn from it and you get up and do it again, only better.
There are few overnight successes, we never truly see the back story behind the latest, hottest new product. We rarely see what went into it to make it the big thing, and we rarely know what went into the company that made that next big thing, we just often see the end result of a lot of ups and downs, trys and retry, so be patient and learn as you go, you will succeed.
Final thought.... do not measure your success by profit margins, not yet. When you're company is employing lots of people and dealing with supply chain, worry about financial success, right now your first success celebration will be just getting 1 website, 1 product. You've succeeded in your first step then and you should be proud.