Doing a patent search is extremely important before you spend time, energy, and money trying to commercialize your product idea. You have to gain an understanding the patent landscape before you begin. You might find a similar idea/invention, at which point you can decide to redesign, find a work-around, or abandon your project. With a little time and education, you can actually do this on your own, but you may also hire professional patents searching firms to provide results.
Patent searches are more of an art than a science. It’s nearly impossible to find all prior art relating to your idea/invention, because there is too much of it. Over time, you develop a sense for what’s important. You can find information at the USPTO website on how you can become proficient in doing this.