Hello. Here's a tip. If you want to start a business it will be much easier and usually less risky to start a business that is a service, rather than a business that sells a product. Here's why. Basically no inventory costs with a service biz. With a product based firm you have the original start up inventory costs to cover. These can be notable. I started a small marketing firm many years ago, and ran it for a long time. It was service based.
That said, if you have read that it takes 5 years to get a start up running smoothly that's about right. Usually your first year is the most challenging. You really need to be prepared to cover your own personal expenses for most of that first year. Here's why. Most income you generate while growing a business will simply cover your costs...inventory, rent, employees, etc. Your 'paycheck' comes at the end, if their are sufficient funds.
One of the best ways to start a business is to work at some company in your area of interest, study what else their customers need and prepare a plan to fill that need on your own. So when you are ready you quit the first company and found yours. Happens a lot. The benefit is that if you are correct in your assessment of needs, you will have a pretty good ready made audience for your new and unique product. Good luck.