F those people that tell you it's not possible. I barely knew how to code and I started a SaaS business. I worked my ass off to become an adequate coder and sell the product to customers. It's been three hard years and now it's starting to pay off. If you have a solution to a problem, one that people will pay for. You have a business. Keep pushing. You can do anything if you're willing to work hard for it. Take help when you can get it. Learn everything you can. Enjoy the journey.
If you're looking for a final external "push" from a stranger, you've come to the right place. Start it. Build the thing you envision. Don't worry about competition in your space for now. Build the best product you can. Learn the stuff you want to learn. Show it to people. Talk about it with clients. Life is short and you only get one shot at it.