These days there are many people who have been asking this question: " How do I apply for a patent? " Get a product that is patentable. By being worthy of patent we mean a product that is different from other existent products. Now, it is possible that you have come up with a product that is not exactly 'different' from other products but is a remarkable improvement on it.
For instance, there are electrical kettles in the market and then you come up with an electric kettle that has not cord and can be charged by putting it on a metal base. You deserve a patent for the product because it is such an improvement on the kettle that though it still remains a kettle to be used in the same manner but it is remarkably different from all the kettles in the market.
Therefore, patent is granted for the products that are new in some respect. It does not mean that even the idea should not have existed. There can be something that is used in one way. You may come up with something that does the same work in a different way. It too is patentable.
Now, if you have such a distinctive product, you could get it registered with the patents office and your patented product or designed cannot be used without your permission. This means that for a limited period of time you have exclusive rights to make use of what you have invented and whoever uses is has to pay something to you for that use even if he is taking nothing from you.
The fact that he is using what you have invented makes you deserve a royalty. Now, let's come to the real question. You can start by finding a lawyer to get you a patent. There are all kinds of lawyers out there. They can be very expensive and can also be relatively cheap. The sum of money that you pay does not make him a big shot but because he is a big shot that you pay him that much.
If you're looking for a recommendation, we suggest you get in touch with InventHelp, they have been in this industry for a long time, and helping innovators to patent and market their products and ideas. You can visit their official YouTube channel here: https://www.youtube.com/user/inventhelp
However, what doesn't matter to you is how much experience or name he has made for himself. You have to find out if he is a successful patent lawyer. A seasoned patent lawyer would know not only the law but also the way the wind is blowing in the patent world. You can learn how InventHelp, a patent attorney, can help you patent your idea/product easily here: https://campuspress.yale.edu/tribune/inventhelp-gets-great-inventions-from-the-mind-to-the-market/
His work is to get you a patent as soon as he could and the sooner, the better. So, you should go for the lawyer how is known to get it done lightning fast. He is your man. And he would do the rest. I guess your question, "how do I apply for a patent?" is not longer a question. If the doubts remain, your lawyer would surely remove all of them for small fees.