There’s a “hub” accessible only to League Cycling Instructors (LCIs) on the League of American Bicyclist’s website, and an LCI in Denver asked if anyone was making money from teaching. I shared how I was hired by a city to teach Seniors-on-Trikes (plus other classes). The city had purchased the trikes, so I showed up and taught. But there is a potential bigger biz opportunity if you are able to purchase adult trikes yourself and travel around with them to senior centers, corporations, parks, etc. for a fee.
I linked to the document that I share for free as part of my Bonus Resources, with recommendations for teaching the class for anyone to reference. There are also stories about the classes, and more, in my book, Traveling at the Speed of Bike.
Note: I am currently in the business of selling books. With a portion of proceeds from the sale of books, I offer classes for free to women (including seniors) and girls who are new or returning to bikes. Your support is greatly appreciated.