Here's a few things to consider when doing research on a complete defensive shooting class (not a basic shooting course).
1. Marksmanship--defensive shooting requires mastery of non-sighted techniques. However, while most defense shootings occur within a couple yards, some do not. Learning to use sights under duress is essential when the exposed target is reduced. Be wary of those who keep all training within 5 yards on over-sized targets. Teaching accuracy is beyond the ability of most instructors; the easy money is in selling squat-point-jerk. A complete education requires you to be able to fire at a few car lengths (at least) under duress. Don't let anybody talk you out of it.
2. Angles--stances and positions are worthwhile but defensive shooters may have to fire sideways, from the ground, up and down. Defenders may not be able to square off on the target. A good instructor will know that.
3. Support hand firing--you can't fly away if your shooting arm gets broken or a second attacker grabs your shooting arm. Every defender must be able to draw, manipulate and fire with the support hand. That's common sense and it needs more than five minutes of training.
4. Entry requirements--if anybody can attend without a minimum of safety, firearm operation, or marksmanship competence, the school is probably a cheap Rambo-target course with all hands on line jerking away shots at a big, close target. You don't need to pay somebody for that.
There's a lot of great instructors and schools out there. The NRA is a good place to start. Do your homework before you commit.