Go to your department of insurance website, start obtaining the classes, and start taking the tests to get your license. Some insurance companies will hire you and put you through the classes and licensing too.
The department of insurance in your state can be found by searching for "your-state-name + insurance department" in Google.com. For example, "California Insurance Department". From this website you will be able to determine the number of credit hours you need to earn through approved insurance license courses.
In order to fulfill the insurance license course credit hour requirements, you will need to take the course through an approved provider in your state. It depends, if your state accepts online courses and self-study option apart from classroom courses, you can take those as well from the convenience of your home or office.
Once you have completed the coursework with the provider institute or online school, they will report your credits back to the state department which will qualify you to take the state insurance license exam.
When you pass the exam, you will become an insurance agent and be licensed to practice as one. An insurance company might pay for the insurance license courses that you need to fulfill as part of the requirement to take the exam.