If you're not sure whether to commit to buying a license, you can fish for free in any Texas State Park—many will even lend you gear and tackle. Saltwater and inshore anglers will find coastal Texas, near the Louisiana border, as well as the area near South Padre Island much to their liking. Catfish anglers flock to the Trinity River, along with Lavon Lake and Lake Ray Hubbard for monsters. Bass chasers love Sam Rayburn Reservoir for the opportunities it presents.
Check out these Lewisville, TX fishing resources: