A question asked by a significant number of inventors is: Am I free to create and sell a product if I don't have a patent on my invention? The simple answer is that you don't need a patent to make and sell a product.
A patent gives you, the inventor, the right to prevent others from making, using or selling your invention, as claimed in the issued patent. So, your patent is a tool for maximizing your market share, and may also be licensed (that is rented) to others. Not having a patent will not be a problem at all if your invention and product is in a relatively niche market. If your market is local and not really large, no problem. If your product has a potential of selling nationally and of having a broad public interest, having a patent is far more valuable.
Having said the above, there is the separate question of whether or not your product may violate one or more claims of a valid patent belonging to someone else. This issue can be resolved with what is called a “freedom to operate” search. Such searches are performed by a variety of enterprises.