You could start with finding a fitness instructor in your area and asking if you would be able to shadow them for a few training sessions. If you can, I would try to find at least 2 different trainers to follow a few times. This will give you a better idea of what being an insturctor entails.
It would be good to actually hire a trainer for a fitness assessment and a few sessions as well.
I do teach Fitness Instructor courses and CECs, but I teach them in Hawaii. Though I will travel to a site that wants a workshop or seminar.