You are very intelligent for a 60-year-old! So, you don't need to worry too much.
Making money is important, of course!
Besides Medium, I only know about Substack. You could also try posting on Instagram and creating reels.
In my country, influencers earn a lot from Instagram and YouTube.
Writers have accounts on Medium where they can share excerpts from their writings as posts or reels, or simply come on camera to share their thoughts as reels.
Not sure what would work best for you, but all the best!