1st of all, thank you for your service to the USA, Semper Fi. NRA is an excellent place to begin. It'll tell you where, when, to go and get the courses and certifications on becoming a instructor, RSO, coach. I'm in the process of achieving my 4th instructor discipline; IAW, certified rifle/pistol instructor, Range Safety Officer, etc. Just a suggestion for a starting point, the NRA, and I hope you'll enjoy volunteering your skills to Boy Scouts, 4-H clubs of America, others. If you can make a "living" at being an instructor or a coach, more power to 'ya. You'll see that when you seek training, most all of it will be taught by volunteer instructors. I know guys who do alright by making dollars teaching CCL classes and self protection courses part-time. The least that'll happen is being able to enjoy this gun forum. Enjoy life.