Lake Carolyn is posted no fishing all the way around it. But if you look on google there are lots of ponds / canals that you can get to in Irving. Look around Royal Lane & George bush, Mac Arther and 114. The water that flows out of Hackberry Creek golf course is not to bad. Any pond in the middle of a park is fair game.
I am far from an expert fisherman, but I usually throw a lipless crankbait , roadrunner jig head with pearl curly tail grub and if that fails then slow it down with a wacky rigged senko or a texas rigged worm.
Good Luck and watch for snakes when in the tall grass or do like I do and stay on the sides with the mowed grass