Texas has organized its open data into a portal for easy access. It's sections include: blockchain, permits & licensing, business & economy, government & taxes, social services, transportation, agriculture, veteran, education, public safety, energy and environment, and public reports and maps.
While you don't need to register for an account to browse and view data, you can sign up for a free account to create filtered views of data and visualizations.
For information on how to search the portal and make use of the information, check out the Guide to the Texas Open Data Portal.
In addition to the main Open Data Portal, Texas has some other datahubs:
The United States Government's website for finding data, tools and resources to conduct research and design visualizations.
For details on how to search Data.gov for information, check out the Data.gov User Guide.
In addition to the large portals for Texas and the U.S., most local government organizations also have a way of searching the open data that they compile.
The following resources are available for the Harris County and Houston area. Search Google with the name of your city or county and the keywords "open data" to see what is available for your local region.