There are many, many types of insurance that a person can purchase. The types most people first think of are life insurance, home owners insurance, and auto insurance. Beyond these you have health, disability, credit, commercial, flood, etc.
Every State has their own laws regulating insurance plus there are Federal Laws that apply to the States. Further each type of insurance, such as those listed in the prior paragraph have laws that are specific to that type of insurance in addition to the general laws of insurance that may exist at the State and Federal level.
The laws dealing with and regulating auto insurance can be found in some obvious places, such as the Texas Insurance Code and at the Texas Department of Insurance. An attorney in Dallas, Fort Worth, Arlington, Grand Prairie, Weatherford, or anywhere else in Texas may not even know that the Insurance Code exists. As for the Texas Department of Insurance, most attorneys would know there is an agency that deals with insurance that is run by the State but may not know its name.