Should I start teaching classes before getting certified?

Rob- Yes do get certified but before you do that take as many classes as possible from many different instructors to see the different styles of teaching. Do Do Do shadow someone and see if you can eventually co-teach with your mentor. I suggest a smaller class where the participants are consistent and will be understanding with you learning. The certification will help you understand the differences between teaching a group and a individual. One thing you will also need to get if you are looking to get certified, is your CPR certification, do you have that yet?
Good Luck!