In the past, starting a business required a relatively large expenditure on infrastructure. You needed a storefront, or at least some place to set up shop where people could see the company's products or services. You probably needed to consult with a bank for funding or rely on the generosity of friends and family. Reaching your target consumer often involved being in the same geographic location as they. Simply put, it was an onerous process with significant entry barriers.
That's no longer true. Now, incorporating your business can be a straightforward, inexpensive process.
There are no guarantees of success, but what you can ensure is that you have the opportunity to succeed. A domain name, a registered agent fee and an employee identification number represent a tiny fraction of your potential profits. However, in order to realize these sorts of lofty ambitions, it will take a combination of careful planning and hard work.
It starts with an idea. If yours is too general to start with (say, "I want to make textbooks less expensive"), figure out the concrete service you will provide to make that happen. Analyze the target market and competitors, and then formulate an action plan.
You'll also need to get the word out. Be willing to talk about your idea, and be passionate about your venture, but don't resort to spam. Instead, tell people a compelling story that adds value to their lives. Not only will they be more likely to retell that story, you may find that they are eager to help out.
Waiting is doing a disservice to yourself. It's impossible to succeed without starting, and the longer you delay, the more time there is for somebody to come up with a product or idea that renders yours obsolete.