Starting or running a business is not for everyone. You need to take an honest look at yourself and the reasons you want to run your own business before you get started. Are you good at thinking about the "big picture"? Can you handle the pressure of being the one person responsible for the success or failure of your business? Do you have a personality that will make you an effective seller of your ideas?
Starting a new business means you have to wear many hats. You probably won't have enough money to hire people to do everything, so you'll end up being the accountant, graphic designer, administrative staff, technical support, and much more. Know your limits. If you don't have experience in certain areas, like legal issues or bookkeeping, get help. If you don't, you could be in serious trouble later and you can ruin your reputation if you don't do a job well or on time.
You should also know your limits on financial issues. Lots of businesses have gotten into serious debt by putting too much hope into getting big returns too soon. Make sure you have a "Plan B." What happens if your business fails before you start making any profits? Have you borrowed more money than you can pay off if that happens? If you have rent and staff expenses, you have to be sure you can pay for long-term contracts. You'll be in trouble if you sign a 2-year lease and your business fails in six months. You'll also need unemployment insurance to cover any employees you'll have to let go.