I’m interested in coach training and the Graduate Diploma, but not sure where to begin or what I’ll end up completing. Do I need to decide before registering?

Short answer; no!  You can enrol in just Level 1 to get a taste of IECL coach training and then decide from there. If you decide to complete an Organisational Coaching and Leadership graduate degree at CSU at any point you can always use your IECL Levels 1 to 3 (with additional assessments) and “Principles of Organisational Coaching” as full credit subjects in your CSU degree.