Query About Marketing and Media Influencers

Hello again!

I'm back for some friendly advice. Many thanks to those of you who have given me your advice in the past. It's much appreciated.

I'm currently working on a course for fitness, plant-based nutrition and weightloss. It will be offered online on my Website at healthylifecourse through a gated user/pass protocol. I will offer a text version of the course, as well as an audio version. The Website right now is sort of a temporary place-holder for people who just happen to bump into it, or who find my video on YouTube. I will still use the same URL for the course, but the site will be redone. I'm considering using a long-form sales page, but that will be the subject of another post on the warrior forum.
I'm not sure about the pricing yet, but I'm thinking around $50. The course will be the equivalent of about a 300-400 page e-book.

My marketing plan is based on my USP that I'm 75 years old, and in excellent shape (watch my video on my site), and have been following a plant-based diet for more than 10 years. My belief is that my story has enough content that I can get influencers to interview and thus promote me.
I have several possible venues that I will be approaching. One is television, which is kind of a long shot, but plant-based nutrition is a very hot topic now. Last year, TV personality Steve Harvey did a section of his show on plant-based nutrition. I haven't watched TV since 2003, so I don't know who or what is on there, but it's one possible option.

More realistically, I will be looking at Internet-based influencers, both on venues like YouTube and on social media. I've found a couple of sites that list health-based channels.

I'm asking for any advice or tips you have for my marketing campaign. Is it worth hiring someone? What could they do that I can't? What are good sources to find the best influencers? I anticipate releasing my course around May or June, but I want to get everything lined up ahead of time.

Thanks a lot in advance!

KnowOne