Best Way to Sell Workout Programs Online?

I am a long-time swimmer and swim coach looking to sell individually curated swimming routines, fitness and nutrition plans, online but am unsure where I should market them. I was hoping to start coaching in the Spring but due to various reasons won't be able to so instead, I'm planning to create and sell plans/work with swimmers virtually.

Some places I've considered include Fiverr or a personal website.