I'm a business major and I will tell you for a business to turn a profit is hard in general. Doable, what your wanting to do is great. I will caution you when you run your numbers make sure you read up on tax law. Vehicles are so tricky when involve them in a business plan unless you buy a vehicle just for your business. Honestly I would take others advise and on a Saturday I would invest in some bolts or just fat quarters and open a booth locally or ask permission at a church to set up after service if allowed. See what your market is and you have to get the local flavor. Is it country, modern, loud, bright, pastels, solids, prints or scrappy fabric that's the top seller.
Good luck and I hope you achieve all your goals, it can be done!!