Fishing for Carp & Gar are 2 totally different fishing experiences. Carp, half the fun is learning how to bring the fish to you. Gar, half the fun is sight fishing for them, finding out where they are at and then fishing for them.
I believe there is some Alligator Gar in Waco, in the Brazos and perhaps also in the main lake. But the technique I'm mentioning here is for Longnose Gar. I like to use a small bream on a hook, bobber, about 1-2ft from the surface. Cast out near the fish after you see them surface for air. (Primarily in the hotter months.) You can also put nylon rope on the hook to help tangle the teeth in the rope which catches them as well.
For Carp, the best way to get started is to find an open area. Throw out 2-3 cans for sweet corn as far and wide as you can. Bait up using a small hook, string about 6 corn kernels PAST the hook on the line and then also place a few on the hook itself. Place the line in free spool and on a rod holder. When line starts going out, gently set the hook, do not be too aggressive since the Carp's mouth is soft. Some people like to suggest 10-20lb test, but I like to error on the side of caution, so if possible use a 35lb braid or heavier as your main line.
Get some coffee, a few snacks, etc, and type this phrase into Google and prepare to wonder where the day went after you get absorbed reading all the information.
"european carp fishing techniques"
I also went straight from bass fishing to carp fishing. After that first fish, never went back.