Ask HN: Coaching as my next career at 63?

I'm 61 and have 10 years experience as a scrum coach. I am a development manager and very part time developer for a team of 3 total at a University. I have coached individuals ad-hoc successfully several times with many staying in close contact and thankful for my help. All pro-bono. I mentor high school students in STEM career choices on an ongoing basis also pro-bono. I will have the chance to retire in two years and have been assured that I can find lucrative scrum coaching work as a contractor. But, I don't want to be coaching scrum all day. I would rather be coaching the development of professionals. I have built and sold two small businesses, have been a successful systems integrator and business systems analyst and a bank compliance advisor. So I am not afraid of new things. I'm told I have very good interpersonal skills for someone technical. I'm planning on getting certified in some coaching disciplines like Gallops Strengths Finder (which I love SF) in the next two years. What certifications should I avoid and what might be good to consider? What other advice do you have for me?