Hi Mike,
You don’t need to have your patent before you start pitching your idea to a company. What you need is to apply for a patent first to try and maintain some level of control or protection on your idea, and only then try to pitch or sell your idea to the company to see if they would be willing to buy or license your patent application from you.
Also, be very careful about working with any company that wants to charge you money to help you sell or license your invention. Many of these companies are scams and even the ones that are legit have a very low success rate and make most of their money from inventors like you paying them.