Sometimes (not always) it’s possible to start with what you already have. My sewing business started with a sewing machine that had been in the family for ages, and a costume shop owner who was willing to supply the fabric.
I was lucky, though.
But it was grand while it lasted!
People need skills and tools. Today, with the Internet, you can market online and to targeted markets.
I know someone with a business similar to yours. She began making re-enactment clothing for herself and friends and now sells at a couple of large Western or Rendezvous-type shows, on the Internet and out of her own shop.
Yes, you live out of the cash box and maybe have no employees except one or two other talented folks to help out when there is a rush job or one too big for one person. But you can make enough to live on or to supplement a day job and if you are good at what you do, the clientele will follow, mostly through word-of-mouth, which is the best and cheapest advertising in the world.